A2:

USS Defiant (Star Trek: Deep Space Nine)
Hammerhead fighter (Space: Above and Beyond)

A3:

Borg Cube (Star Trek)
X-Wing (Star Wars)

A4:

The Death Star II (Star Wars)

A5:

A6:

Babylon 5 (in the background, spanning a large area from A6 to D3)
Klingon D7-class battlecruiser (Star Trek) (Also A7)
Space Vampire Mothership (Lifeforce)

A7:

Romulan Warbird [behind D7 and White Star] (Star Trek: TNG, DS9, VOY) (Also A6, A8, B6, B7)
White Star (Babylon 5) (also B7)

A8:

Romulan Bird of Prey (Star Trek: TOS)

A9:

Zanti, The Zanti Misfits (Outer Limits 1963)

A10:

Zanti, The Zanti Misfits (Outer Limits 1963)

A11:

A12:

Space Herpes (Ice Pirates)

B1:

Colonial Viper (Battlestar Galactica)
"Nell" ship (Battle Beyond the Stars (1980))

B2:

Imperial Star Destroyer (Star Wars)
Ghost (Star Wars Rebels)

B3:

UD-4L Cheyenne Dropship, Sulaco (Aliens, 1986)

B4:

USS Enterprise-D (Star Trek: The Next Generation)

B5:

Star Fury (Babylon 5) [Also B6, C5, C6]

B6:

Warp core [Through B6:K7]
Eagle Transporter, Space: 1999 (1975)
Fighter (Buck Rogers in the 25th Century)

B7:

Eagle 5 (Spaceballs)

B8:

Battlestar Galactica (Battlestar Galactica)
Moya (Farscape) (Also B9)
Jetfire (Transformers) (Also B9)

B9:

Moya (Farscape) continued

B10:

Zanti, The Zanti Misfits (Outer Limits 1963)

B11:

Gremlin (Gremlins)

B12:

Ceti Eel, a parasitic arthropod from Ceti Alpha V (Star Trek II: The Wrath of Khan, 1982) (also C12)
Crystal Bat (The Dark Crystal)

C1:

The Millennium Falcon (Star Wars)

C2:

USS Palomino (The Black Hole, 1979)

C3:

Bebop (Cowboy Bebop) (also D3)
Paranoid battlesuit (Gall Force: Eternal Story) (also at C4, D4)

C4:

Planet Express Ship (Futurama)
Ravager M-ship, The Milano (Guardians of the Galaxy) (also at C3, D4)

C5:

Radiant VII (Star Wars: Episode I - The Phantom Menace)
USS Enterprise (Star Trek: The Original Series)

C6:

Narcissus, Nostromo Lifeboat (Alien 1979, Aliens 1986)

C7:

C8:

Engineer Ship (Alien 1979, Prometheus 2012)
Nebulon-B Frigate (hospital ship, Star Wars: Episode V - The Empire Strikes Back, Star Wars: Episode VI - Return of the Jedi)

C9:

USS Discovery One (2001: A Space Odyssey)

C10:

C11:

Zanti, The Zanti Misfits (Outer Limits 1963)

C12:

Ceti Eel, a parasitic arthropod from Ceti Alpha V (Star Trek II: The Wrath of Khan, 1982) (continued from B12)

D1:

Insignia: Cylon Empire (Battlestar Galactica)
Insignia: Colonial Warrior (Battlestar Galactica)

D2:

Insignia: Rebel Alliance (Star Wars, continues D1)

D3:

Imperial Probe Droid (Star Wars)

D4:

Close Encounters of the Third Kind mothership (also D5)
Viper (BSG)

D5:

Rodger Young (Starship Troopers)

D6:

USS Voyager (Star Trek: Voyager)
Serenity (Firefly)

D7:

USS Swinetrek (The Muppet Show: "Pigs in Space")
Giant dragonfly "insect", Nausicaä of the Valley of the Wind (1984)

D8:

D9:

Insignia: Klingon Empire (Star Trek)

D10:

Max (Flight of the Navigator, 1986)

D11:

Pit Droid folded up (Star Wars: Episode I - The Phantom Menace)

D12:

Impossible Man (Marvel Comics)

E1:

Bioraptor (Riddick)

E2:

E3:

E4:

Insignia: Galactic Empire (Star Wars)
Insignia: Robotech Defense Force (Robotech)

E5:

Insignia: ThunderCats

E6:

Insignia: Tron's chest symbol (Tron)

E7:

Urskeks mandala of The Great Conjunction (The Dark Crystal)

E8:

Lazerbeak (Transformers)

E9:

E10:

E11:

Wall-E and Eve from Wall-E

E12:

Egg and Facehugger (Alien franchise)

F1:

Atari logo
Kilroy from the Mr. Roboto music video by Styx

F2:

Maximilian, The Black Hole (1979)

F3:

Robot Jox mech fight: Achilles (left) vs Alexander (right)

F4:

V.I.N.CENT, The Black Hole

F5:

Spider-Man, in alien symbiote suit (Marvel Comics)

F6:

F7:

Optimus Prime (Transformers) (also F8)

F8:

Iron Giant from The Iron Giant (left hand appears in G9 and H9)

F9:

Thunder Road, modified Tilt-A-Whirl car (Explorer's 1985)

F10:

C-57D Forbidden Planet (1956)
Jupiter 2, Lost in Space (1965)

F11:

F12:

Huey, Dewey, and Louie from Silent Running (1972)

G1:

"They Live We Sleep" tag from They Live (1988) (continued in G2)
Stargate Ring (Stargate)

G2:

Pan Am logo and Orion III Space Clipper (2001: A Space Odyssey)

G3:

Kuato Lives tag from Total Recall (1990)
Weyland-Yutani symbol, Alien franchise

G4:

V.I.N.CENT, The Black Hole
Logo: Buy'N Large (Wall-E)

G5:

Robocop
Logo: Omni Consumer Products (Robocop)
Diva, The Fifth Element
Zorg Industries Logo, The Fifth Element
Gypsy, Mystery Science Theater 3000 (also G6)
Omar & Angel (Rock & Rule, 1983)

G6:

G7:

Flynn's Arcade sign (Tron, 1982)

G8:

Weebo (Flubber)
crystals from Lifeforce

G9:

Borg Queen (Star Trek: First Contact)
Visitors' poster, defaced by the Resistance (V)

G10:

Rocket Cycle (Flash Gordon, 1980)
Nomad (Star Trek: TOS, episode "The Changeling")

G11:

Tripod, The War of the Worlds (1953)
Endor Shield Generator (Star Wars: Episode VI - Return of the Jedi)
StarChaser (StarChaser: The Legend of Orin, 1985)

G12:

Lambda-class T-4a shuttle (Star Wars)

G13:

Breetai, a Zentraedi commander (Robotech: The Macross Saga)

H1:

Bo (Mighty Orbots)
Barbarella (Barbarella)
Ted Theodore Logan & Bill S. Preston Esq. of the 'Wyld Stallyns' (Bill & Ted's Excellent Adventure, 1989)

H2:

Blue Sun advertisement (Firefly)
A female Vulcan [maybe a specific character?] (Star Trek)
Maria from Metropolis (android form)
Feyd Rautha (Dune, 1984)
Silica (Starchaser: The Legend of Orin, 1985)

H3:

TARDIS (Doctor Who)
Oola, a Twi'lek dancer at Jabba's palace (Star Wars: Episode VI - Return of the Jedi)
Leeloo (The Fifth Element)
Rystáll Sant (Star Wars) (also G3, G4, H4)

H4:

Jabba the Hutt (Star Wars)
A Skeksis (from The Dark Crystal)
Figrin D'an and the Modal Nodes (Star Wars)

H5:

Sy Snootles (Star Wars)

H6:

Data (Star Trek: the Next Generation)
Wak Wak (Explorers, 1985)

H7:

Klaatu (hand raised), The Day The Earth Stood Still (1951)
Barquin D'an (Max Rebo Band) (Star Wars: A New Hope (1977))
Monolith (2001: A Space Odyssey)
Tall alien (Close Encounters of the Third Kind)

H8:

(rear) Gort, (The Day the Earth Stood Still, 1951)
Robot (Lost in Space, 1965-1968)
Robby the Robot (Forbidden Planet)
Johnny 5 (Short Circuit, 1986)

H9:

Marvin, The Hitchhiker's Guide to the Galaxy (film)
Cheetara, ThunderCats
Lion-O, ThunderCats
Statue of The Lawgiver (Planet of the Apes)

H10:

Nomad - ST:TOS "The Changeling"
Atreides Transport (Dune)
Starfleet shuttlecraft (Star Trek)
Luke Skywalker's X-34 landspeeder (Star Wars - Episode IV: A New Hope)

H11:

Starbug (Red Dwarf)
Jake's ship from The Cat from Outer Space

H12:

Superman
Mooncake (Final Space)
Rick, Morty, Mrs Meeseeks, and Rick's UFO (Rick & Morty)
Korben Dallas's flying Taxi (The Fifth Element, H13 - I12)

I1:

Ohno, (Mighty Orbots)
Skeletor (HeMan and the Masters of the Universe)

I2:

I3:

"Marta" Orion Girl (Star Trek:TOS "Whom Gods Destroy") [Also J3]
Twiki, Buck Rogers in the 25th Century

I4:

Lirin Car'n of the Modal Nodes (Star Wars)

I5:

I6:

Dominar Rygel XVI (Farscape)

I7:

I8:

Dalek (Doctor Who)
Cyberman (Doctor Who)
Bender (Futurama)
Alien, Earth vs. the Flying Saucers (1956)
Cylon - Battlestar Galactica (original series)
Kryton, Cat, Lister & Rimmer (I9) (Red Dwarf)
Two Andorians (Star Trek)
Ka D'Argo - Farscape

I9:

Seven of Nine (Star Trek: Voyager)
Mac, Zeebo, and Wiploc (Earth Girls Are Easy)
Aviana & Mizzo (Starchaser: The Legend of Orin, continues I10)
Lumpy (A guess, but all of Chewbacca's family are sitting there, the other two in I11. Just can't tell them apart. The Star Wars Holiday Special)
Zozo (The Adventures of the Galaxy Rangers)
The Moon (Le Voyage Dans la Lun / A Trip to the Moon)

I10:

Borg (Star Trek)
Thark (John Carter of Mars)
Martians from Mars Attacks
Martian from The War of the Worlds
Itchy & Malla (A guess, but all of Chewbacca's family are sitting there, the third in I10. Just can't tell them apart. The Star Wars Holiday Special)
7-90 (Lexx)
Dark Helmet (Spaceballs)
Harry (Harry and the Hendersons)
Gamorrean guard (Star Wars: Episode VI - Return of the Jedi)
A Thermian male (Mathesar?) in human form (Galaxy Quest)
Gwen Demarco / Tawny Madison (Galaxy Quest)

I11:

Waldo Zeptic (The Adventures of the Galaxy Rangers)
Gamorrean guard (Star Wars: Episode VI - Return of the Jedi)
Martian Girl (Lisa Marie), Mars Attacks (1996) (Also J11)

I12:

Chig in space suit (Space: Above and Beyond) (bordering I11)
Predator
Xenomorph from the Alien franchise
Kang and Kodos (behind window) (The Simpsons)
Korben Dallas (The Fifth Element)
Sil, in alien form (Species)

I13:

Zorak (Space Ghost, Coast to Coast)

J1:

Micronauts, Repto (Mego Micronauts Series 4/5)

J2:

A Porg (Star Wars)
A Tribble (Star Trek)

J3:

J4:

J5:

J6:

(?) Horta (Star Trek)
Morn (Star Trek: Deep Space Nine)

J7:

A Quarren (Star Wars)
Alien clown from Killers Klowns from Outer Space
Jem'Hadar (Star Trek: Deep Space Nine)
Scorpious (Farscape)

J8:

Agents K and J (Men in Black)
Jar-Jar Binks (Star Wars)
Ruby Rhod (The Fifth Element) (also in JK8/9)
Kai Opaka (Star Trek: Deep Space Nine)
Captain Jack Harkness (Doctor Who)

J9:

Vina as an Orion slave girl (Star Trek: TOS)
R2-KT (Star Wars)
Gorn (Star Trek: TOS)
Det. George Francisco (Alien Nation)

J10:

Ewoks (Star Wars)
Mugato (Star Trek: TOS)
Excalbian (Star Trek: TOS, episode "The Savage Curtain")
Talosians (Star Trek: TOS)
Jean-Luc Picard (Star Trek: The Next Generation)
William T. Riker (Star Trek: The Next Generation)

J11:

Nog and Rom (Star Trek: Deep Space Nine)
Two Breen soldiers
Q in his Judge costume (Star Trek: The Next Generation)
Lore (Star Trek: The Next Generation)
Boba Fett (Star Wars)
Spock (Star Trek: The Original Series)
Leonard McCoy (Star Trek: The Original Series)
Nien Nunb (Star Wars)

J12:

Darth Talon (Star Wars (Legends))
Mace Windu (Star Wars)
BB-8 (Star Wars: The Force Awakens)
A Vorvon (Buck Rogers in the 25th Century, "Space Vampire")
A Red Lectroid (The Adventures of Buckaroo Banzai Across the 8th Dimension)
(?) Michael (The Good Place)

K1:

K2:

Darth Vader (Star Wars) (only right arm and buttons of the suit visible)

K3:

Wuher, the bartender from Mos Eisley cantina (Star Wars)

K4:

Kuato (Total Recall, 1990)
He-Man (He-Man and the Masters of the Universe cartoon, 1983-1985) (continued in K5)

K5:

Dragon noodle parlor neon sign (Blade Runner) [also in K4]
Lightsaber (Star Wars)

K6:

Salacious B. Crumb (Star Wars: Episode VI - Return of the Jedi, 1983)
Ackmena (The Star Wars Holiday Special)

K7:

Damar (Star Trek: Deep Space Nine)
Roth'h'ar Sarris, main antagonist of Galaxy Quest (also in L7)
Kabe (Star Wars)

K8:

Tarfful (Star Wars)
Ripley and Jonesy (cat) from Alien

K9:

Alien from Mars Attacks (being strangled)
Stormtroopers, Star Wars
Paul Atreides from Dune, pre-Muad'Dib attire

K10:

Stormtroopers (Star Wars)
James T. Kirk (Star Trek: TOS)
Drac Jeriba and Zammis (Enemy Mine)
Qui-Gon Jinn (Star Wars) (also L10)

K11:

Han (Star Wars)
Leia (Star Wars)
Greedo (Star Wars: Episode IV - A New Hope)
C3-PO (Star Wars)

K12:

Momaw Nadon (Star Wars: Episode IV - A New Hope)
Ewok, possibly Chief Chirpa? (Star Wars: Episode VI - Return of the Jedi)
Admiral Ackbar (Star Wars: Episode VI - Return of the Jedi)
Col. Wilma Deering (Buck Rogers in the 25th Century, 1979)
Scout Trooper (Star Wars: Episode VI - Return of the Jedi)

L1:

Ming the Merciless (Flash Gordon, 1980) — chest and arms
Tom Servo and Crow T. Robot (MST3K) (continued in M1)

L2:

Simon game
Dancing Alien (Spaceballs)

L3:

Max Headroom (on TV screen)
Saurian brandy bottle (Star Trek)
Kanar bottle (Star Trek: Deep Space Nine)
Flag of the United Citizen Federation / Terran Federation (Starship Troopers)

L4:

Aviana's riding helmet (StarChaser: The Legend of Orin)
Glaive from Krull

L5:

Guinan (Star Trek: The Next Generation)
H.A.L. 9000 (2001: A Space Odyssey)
Zik-Zak Corp. logo (Max Headroom series) (also L4)
Sword of Omens (Thunder Cats, continued in L6)

L6:

Gigolo Joe (A.I. Artificial Intelligence 2001) (continued in M6)
Facehugger as seen in Ash's lab (Alien)

L7:

Princess Aura (Flash Gordon, 1980)

L8:

Pampy, Twi'lek aide to Senator Orn Free Taa (Star Wars: Episode II - Attack of the Clones)

L9:

Jessica Atreides (Dune)
Communicator from Star Trek (on the floor)
Nyota Uhura, Star Trek: TOS

L10:

Rose (Star Wars)
Finn (Star Wars)
Aeryn Sun (Farscape) (also M10)
John Crichton (Farscape) (also M10)
Mara Jade (Star Wars)

L11:

R2-D2 (Star Wars)
Thrawn (Star Wars)
Waldo (robot-version) (Where's Waldo?) (continued in L12,M11,M12)

L12:

Scout trooper (Star Wars)
(Possibly) Luke Skywalker's Hands (Star Wars) (continued M12)
Schwartz Ring (Spaceballs)
Erin "Dart" Bia O'Rourke-Singh, white-haired woman, from the 2nd Atari Force team

M1:

Tom Servo and Crow T. Robot (MST3K) (continued from L1)

M2:

"Obey and Conform" sign (They Live)

M3:

Quark (Star Trek: Deep Space Nine)
RYLOS license plate (The Last Starfighter) (also M2/N2/N3)

M4:

M5:

Rick Dekard and Rachael, Blade Runner

M6:

Inara Serra, Firefly

M7:

Krite (Critters)

M8:

Cover of Starlog Number 1, featuring Kirk, Spock, and the USS Enterprise from Star Trek

M9:

M10:

Mutant, This Island Earth (1955)

M11:

M12:

N1:

Thermian (Galaxy Quest)
Bucket of Popplers from Fishy Joe's (Futurama) (bucket visible in W1)

N2:

Donald Kessler and Barbra Land, Mars Attacks

N3:

Gizmo, Gremlins
Londo Mollari, Babylon 5
Jrrr of the planet Omicron Persei 8 (Futurama)

N4:

Baby Groot (Guardians of the Galaxy Vol 2)

N5:

N6:

Christopher Johnson, the alien from District 9 (continued in N7)

N7:

Teddy Bear from AI Ted, or SuperTed?

N8:

Rocket Raccoon (Guardians of the Galaxy)
E.T.
Rick's portal gun (Rick and Morty)

N9:

Alien from Invasion of the Saucer-Men
Saurian brandy bottle (Star Trek)
Mac (Mac and Me), with Big Mac and fries from McDonald's

N10:

Howard the Duck (Marvel Comics)
Paul (Paul)
Alf (Alf)

N11:

N12:

The Great Gazoo, The Flintstones (1965)
Gaff's unicorn origami, Blade Runner
Tribbles (Star Trek)

W1:

A Horga'hn from Planet Risa (Star Trek: The Next Generation)

W2:

G'Kar (Babylon 5)

W3:

W4:

Annelids/worm coffee aliens (Men In Black)

W5:

Chiana, also X5 (Farscape)
MSE-6-series repair droid (Star Wars)

W6:

W7:

Arthur Dent, (The Hitchhiker's Guide to the Galaxy film)

W8:

Yoda (Star Wars)

W9:

Maz Kanata, Star Wars
Auryn Talisman (The Neverending Story)

W10:

W11:

Father "Fix-It", Batteries Not Included (1987)

W12:

Tribbles (Star Trek)

X1:

Merlin game
Possibly a bottle of Romulan Ale

X2:

Mork, Mork and Mindy

X3:

Susan Ivanova and Delenn, Babylon 5

X4:

Annelids/worm coffee aliens from Men In Black

X5:

X6:

Bib Fortuna (Star Wars)

X7:

The Hitchhiker's Guide to the Galaxy

X8:

A Towel. "... the most massively useful thing an interstellar hitchhiker can have."
Kira and Jen, continued in X9 (The Dark Crystal)
Dathon (Star Trek: The Next Generation, "Darmok")

X9:

Jake (The Cat from Outer Space) [Also X10]
Fizgig (The Dark Crystal)

X10:

Barf (Spaceballs)

X11:

Mother "Fix-It", Batteries Not Included (1987)

X12:

A Porg (Star Wars)
Puckmaren, Flight of the Navigator (1986)

Y1:

K-9, Doctor Who

Y2:

Y3:

Y4:

A little golden fuzzy, Little Fuzzy and subsequent works by H. Beam Piper (1962)

Y5:

Y6:

Y7:

Y8:

Y9:

Centauri, The Last Starfighter (1984)

Y10:

Acroyear, Micronauts
Bug, Micronauts (continued in Z10)

Y11:

Wheems & Jetsam "Fix-It" (x2), Batteries Not Included (1987)
Alien from They Live, seen through the special sunglasses

Y12:

Z1:

Frank the Pug, Men In Black

Z2:

Z3:

Dr Zira, Planet of the Apes (1968)

Z4:

Z5:

Robot Monster, Robot Monster (1953)

Z6:

Z7:

Norris-Thing, The Thing

Z8:

Dalgoda, comic book, Jan Strnad and Dennis Fujitake from Fantagraphics

Z9:

Z10:

Bug, from Micronauts (also in Y10)
Jeff Carlisle logo

Z11:

Z12:

Flotsam "Fix-It", (Batteries Not Included, 1987)
Shrunken Kids, (Honey I Shrunk The Kids, 1989)

Art

Another Night at the Warp Core Cafe