Martian Successor Nadesico parodies this trope by introducing Aquamarine, a cookie-cutter character of exactly this type in the Show Within a ShowGekiganger 3. The protagonist Akito immediately identifies her as his dream girl, but when he finally meets a young woman with a similar name (just "Aqua") who appears superficially similar, she turns out to be a borderline psychotic with suicidal tendencies.
To Love-Ru has a fair number of these, of both genders: three Devilukean princesses Lala, Momo and Nana, Zastin, Lala's father back in the days, Ren and Run, Yami and Mea, Dr. Mikado and Tearju Lunatique.
Super Dimension Fortress Macross, features a Green Haired Space Babe: Miria Fallyna is especially notable for falling in love with her target after losing to him in battle then seeking him out to defeat him on board the ship. He runs into her at an arcade where he defeats her in a video game. He misunderstands her intentions and asks her on a date at which she tries to kill him with a knife. He wins again and she breaks down since he's the first person she's never been able to beat.
Notably, among all the similarities between Macross and the other two series' used to make Robotech is that all three of them have a green-haired alien girl who ends up falling for one of the good guys: Musica in Southern Cross and Sara in Mospeada.
Dragonball has Zangya, and the advent of Dragon Ball On-Line brought us the Majin race and several pink skinned space babes.
Keroro Gunsou has several, ranging from regular character Angol Mois to Space Policewoman Poyon to single-appearance ones.
Xavin of Runaways achieved this with his/her female Skrull form.
Xavin's lover Karolina 'L.S.D.' Dean is a Iridescent/Psychedelic-Skinned Space Babe in her own right.
Gamora, who fits this trope to a tee, right down to the, ah, appetite. She's also immortal, an assassin, and recognized as "the most dangerous woman in the galaxy".
Used delightfully but deceptively in Top 10 in the form of retired heroine/alien pornstar M'rgalla Qualtz, the Vigilante from Venus. Her true form turned out to be a huge green insect thing
Lyja is another example of an attractive female Skrull, who Johnny Storm fell in love with after he got over the whole Skrull thing.
Long before that, in the early Lee/Kirby era, there was an instance of mutual attraction between Johnny and the Skrull princess Anelle (who later became Hulkling's mother because of a tryst with Captain Mar-Vell. And during the Byrne era, he was by no means immune to the charms of green-skinned Earth babe She-Hulk. Who later whould hang out with the sexy Skrull bounty-hunter Jazinda.
De'Lila is a Skrull Space Babe who can also hypnotise you.
Teen Titans: Starfire first appeared as a hot alien babe with orange skin, who learned languages by kissing people. Her general lack of modesty is often used for copious Fanservice, and even her normal hero outfit leaves little to the imagination.
Miss Martian, who in an interesting twist is actually a White Martian and monstrously inhuman and hideous in her true form. Think "albino xenomorph".
Parodied in Heater Delight, space "commodity" and sometimes-girlfriend of Marvel's Starfox.
Jimmy Olsen had Forager for a love interest Alien babe.
The Green Lantern Corps being what it is, there are plenty of Green Skinned Space Babes to go around: Katma Tui, Soranik Natu and Arisia Rrab, for example.
Kraken started as a literal example, complete with midriff-baring outfit, although her conversion into an Alpha Lantern made her much less attractive.
Princess Arkashia, a one-shot character from Empowered, with whom not-yet-Protean sleeps with, catches an alien STD and thus turns from a human into the Blob Monster we know him as.
In the Ice Sword saga in the Italian Mickey Mouse comics, Goofy is chosen to awaken a sleeping princess who has been sent by a shooting star. He first imagines her as a human Princess Classic, but when he finally sees her, he is surprised to see that she is a green-skinned, noseless alien with gigantic bug-like (though cartoony) eyes... Despite this, he still finds her cute.
Tanga, a lavender-skinned space babe super heroine created by Kevin Maguire for the comic book Weird Worlds and My Greatest Adventure.
Being what it is, Legion of Super-Heroes has had a few over the years. Foremost among them is Shadow Lass/Umbra, a blue-skinned space babe.
The water girl in King City is a blue, tentacle-haired, tailed water-breather, but looks otherwise like a cute human woman.
Film
Female Twi'leks from the Star Wars universe are known for their beauty, and often exploited due to it. They come in green, blue, red, and other interesting hues. The first Twilek female was seen in Return of the Jedi, Oola, Jabba the Hutt's ill-fated dancing girl who ends up Rancor chow.
Sebulba has a pair of female Twi'leks that he uses as his personal servants. They pretty much act as his massagers and simply as a status symbol.
The Star Wars Expanded Universe has the Zeltron (magenta-skinned), who are perfectly aware of their attractive appearance and flaunt it. Some sources also claim they have mild pheromones, but not to the degree of the Falleen. They have a reputation (mostly deserved) as cheerful hedonists who'll do Anything That Moves. Both genders are like this.
The Falleen (green, but red when excited), who in addition to all being drop-dead gorgeous have powerful sex pheromones under conscious control that work on nearly all humanoid species.
Blue-skinned women run a Lady Land society in the 60's B-MovieMissile to the Moon. Only in the colorized version, this originally being a B&W film. The GSSB attitude was there from the beginning, though.
Avatar has the Na'vi, male and female. Appropriately, the main character falls in love with and has sex with one of them.
Male example in Earth Girls Are Easy. We have Blue, Red, and Yellow Alien Space Hunks in the forms of Jim Carrey, Jeff Goldblum and Damon Wayans. But only when their body fur is shaved off.
"You know, sometimes I wish I did a little more with my life instead of hanging out in front of places selling weed and shit. Like, maybe be an animal doctor. Why not me? I like seals and shit. Or maybe an astronaut. Yeah. Like, be the first motherfucker to see a new galaxy, or find a new alien lifeform... and fuck it. And people'd be like, "There he goes. Homeboy fucked a Martian once."
Another male example: Loki's true Jotun form in Thor, down to the weird exception-to-the-species factor often seen only in female examples. The rest of the Jotuns are hulking, craggy monsters; in the brief glimpses we see of Loki's Jotun form, he looks the same as ever except for having swirl-patterned blue skin and vaguely luminescent red eyes.
Literature
Dejah Thoris of the John Carter of Mars series is a red-skinned space babe; apart from that, she may be the ur-example.
Though not portrayed as sexy (she is from a book written in 1897 by a German science teacher), the Martian La from Auf zwei Planeten (Two Planets) by Kurd Laßwitz is shown as attractive. She has large eyes that change color and reddish-blond hair. She ends up marrying Earthman Josef Saltner.
In the Viagens Interplanetarias cycle by L. Sprague de Camp, one of the prominent planets, Krishna, is populated by a humanoid species that happens to be sexually compatible with humans (though matings won't result in offspring). Some of them wear nothing but jewellery and body paint. Needless to say, one of the human characters gets to seduce a local princess. De Camp knew exactly how unlikely this would be, but wanted to write swashbuckling, two-fisted adventure stories but in space, and worked very hard to come up with a setting that would let him get away with this, without being as utterly stupid as the premise of the John Carter of Mars series. The biological difficulties are frequently lampshaded, and provide a fair amount of the comedy in the series.
A short story by James Tiptree, Your Haploid Heart, features an outwardly humanoid and physically seductive human species (the Flenni), but the problem is that they happen to be just a phase in a complex reproductive cycle, and their post-coitum lifespan is counted in weeks.
The Queen of Perelandra is her world's Eve, and thus the first of many Green Skinned Space Babes to appear on Venus...although she's shielded from the protagonist by an aura of innocence.
Fyana, in John Maddox Roberts's Stormlands series, is a Blue-Skinned Post-Apocalyptic Mutant Babe.
The Trope Namer is literal Green Skinned Space Babe Vina, played by the late actress and director Susan Oliver, all the way back in "The Cage", the first Star Trek pilot. Well, the green Orion slave girl was one of the guises that her character took, at least. Interestingly enough, it was the one Pike was almost certainly going to fall for, before stuff happened.
TOS also featured a Green-Haired Space Babe in the person of Shahna the Drill Thrall, in the episode "The Gamesters of Triskelion." Her ignorance of kissing is possibly the original source of another trope, What Is This Thing You Call Love?, applied to space aliens; she requested another example from Kirk to broaden her sample set.
Jadzia Dax (the spots go all the way down). More intellectual than the usual Space Babe, but sexy as hell and perfectly willing to indulge her sensual side (her prior male host was a Dirty Old Man, and it seems the libido carried over).
Mocked on Frasier, when Noel attempts to immortalize Roz by making her a character in the Star Trek universe.
Shephard from Stargate Atlantis usually gets the space babe, so in the episode "Harmony", Rodney demands the first chance at the eponymous princess, but then he discovers that she is age 13 and a Royal Brat.
Stargate SG-1 episode "Wormhole X-Treme" lampshaded this in a show within the show.
The Wild Wild West episode "The Night of the Flying Pie Plate" features several literal Green Skinned Space Babes—at least until it's discovered that they're human women painted green as part of a con game.
Lister: I can't wait to see your face in the morning. Rimmer: Nor I yours, Lister, when that pod opens in the morning and from it emerges a beautiful alien woman with long green hair and six breasts.
It turns out that the pod is actually a garbage container. And not an alien one.
A literal green skinned space babe was in Lost in Space. She had a crush on Dr. Smith, who had to use her to find out where to get fuel for their stranded ship.
Aside from the Sebaceans, Farscape lived this trope - if the aliens weren't actually portrayed by Jim Henson puppets, they were certainly as weird-looking and brightly-coloured as possible. Regular characters include Zhaan (blue from head to toe, as her frequent casual nudity will attest), Chiana (entirely grey, and a nymphomaniac to boot), Jool (human-esque, although with forehead ridges, bright green eyes and giant bushes of hair that changes color when she's angry), and Sikozu (Caucasian-colored skin with fish scale-like patterns, red hair, and teal eyes)
Chiana's race, the Nebari (or at least the Nebari most likely to be encountered by other races), seem to have this as their hat, for both the males and females. They're almost all free-love hippie drifters who have no problem at all with casual sex and sometimes have problems with fidelity and settling down. This turns out to be an evil plan by the Nebari government.
Andromeda has Trance Gemini. She's a purple skinned space babe. With a tail.
Quite a few Doctor Who examples, including Chantho and Jabe - the former has mandibles and the latter is technically an Earth-descended humanoid tree. The revival also has (male and female) Silurians for those not put off by scales, in stark contrast to their appearance in the original series.
All of the aliens Tracy Morgan meets in his "Astronaut Jones" sketches on Saturday Night Live.
Music
"My Alien", from Simple Plan:
She has two arms to hold me Four legs to wrap around me She's not your typical girlfriend...
Jamiroquai's "Cosmic Girl":
Step into my transporter So I can teleport ya All around my heavenly body
The Bonzo Dog Doo Dah Band's "Beautiful Zelda" (though in their TV performance she seems to be a rather boxy Robot Girl).
She's broken all the super-hearts Of the super-heroes of the galaxy So why does she want to Mess around with me? Beautiful Zelda from Galaxy Four Suddenly walked through my door
Well, Here's a story that must be told It's kinda new, not very old About a female Martian with a wild grin, Big orange eyes, and green skin Blue was her hair She came from way up there She wore silver underwear Almost naked but she didn't care
Katy Perry plays a white skinned space babe in her video for E.T.
Devo's "Space-Girl Blues," a song from their demo period which was covered by Toni Basil. The lyrics were inspired by an issue of DC's Mystery in Space.
Space girls are as cold as ice They'll kiss you once and kiss you twice You'll shiver, shake, and then turn blue Then you've got the space girl blues I want your mechanism! Give me your mechanism!
The Eldar in Warhammer 40000 are sometimes depicted as this trope. Other depictions however have them be absurdly tall and bony by human standards, with intensely narrow faces (for reference, those two images are supposed to be the same character). In any case it's very unlikely they'd be involved with any humans, as most humans and most Eldar would consider it bestiality, in addition to being EXTRA HERETICAL from the point of view of the humans.
Nazzadi women from Cthulhu Tech are often treated as such by the artists on this project; go through the books and try to find one Nazzadi female who isn't Stripperiffic. The fact that they have no nudity taboo doesn't help matters.
Video Games
Talana, the Syreen commandress from Star Control II, is a textbook example (she even comes from a whole race composed mostly of beautiful blue-skinned women). Given the tone of the game, this is heavily lampshaded.
Elerians, one of the playable races of Master Of Orion 2, are purple and blue-skinned space babes (the males of the species are never seen).
A common enemy in Redneck Rampage is just that; leather clad sadomasochistic big-breasted green/blue/red skinned alien babes who seem very interested in tying up and/or getting beat up by the redneck main characters. Arguably a parody of the trope, as despite claiming to love you they'll just kill you dead unless you kill them first.
The asari of Mass Effect are one of the most blatant examples, with The Art of Mass Effect explicitly stating they were designed from the beginning to be sexy aliens. Not only are they a One Gender Race that look near-identical to human women despite all other aliens being drastically different, not only can the player character enter a relationship with one of them regardless of Shepard's gender, not only are they considered desirable by nearly all species in the known galaxy, but they can mate with and produce offspring with any sapient individual regardless of gender or species (though granted, sex isn't necessary for reproduction). Liaramentions all of this:
Liara: Adolescent males have an unhealthy obsession with my people.
There's also the minor facts that they're the most advanced and powerful race in the galaxy, with many of the deadliest soldiers and the highest percentage of biotics. As in, all of them. Every single Asari is some manner of space wizard from birth, though some don't choose to develop their skills.
Thane, a drell, is a rare male example. Bonus points for being specifically designed to invoke this trope and appeal to the female fans.
Mass Effect 3 finally resolves what Quarians look like underneath their masks, but only if you've romanced Tali andmake sure the quarian fleet survives the battle over Rannoch, and it turns out that they're practically Rubber Forehead Aliens. However, as the "picture" of a Quarian without their mask is a rather badlyphotoshopped stock image of a model◊, most fans put this into Fanon Discontinuity and prefer other, more imaginative fan-made designs.
The Draenei women in World of Warcraft fit this perfectly. Where the males of the species are burly catfish-faced oddities who resemble barely-tethered hot air balloons, the females are much more humanoid.
Garona Halforcen: Green, very attractive, and was born on Draenor, not Azeroth. (Originally she was Half-Human/Half-Orc, then Retconned to Half-Orc/Half-Draenei. This opened several Plot Holes that were somewhat fixed by making her the latter through rape, but making her think she was the former, and making her artificially aged.)
Although they're far from universally attractive, female orcs in general can be this (mixed with a healthy dose of Amazonian Beauty).
Krystal from Star Fox. Bonus points for being a blue space babe in a game whose whole cast already consists of cartoon animals in space.
Aliens in The Sims 2 often come with maxed out Outgoing and Nice. One with a Romance aspiration can be very good at wooing plenty of Sims very quickly.
Even more the case with user-created game mods that change the physical appearances of aliens and alien-offspring, from coloration to facial structure (as the default alien look is a noseless bug-eyed little green man).
Obviously, the Orions in Star Trek Online. The females have the ability to induce confusion, as well as have a natural resistance to confusion and generate less threat than other races thanks to the natural pheromones they give off. As mentioned in the TV section above, the females rule the race (and the Orion Syndicate that rules the race) because of this.
Averted and played with in Girl Genius in the form of the three waitresses/cabaret singers at Madam Gkika's Bar. As far as is so far established, these three are humans disguised as Jägermonster females for the tourist trade. However the three ACTUAL Jägermonsters known as "Da Boyz" seem to find them attractive, which is reciprocated — but of course the Jägerkin are mutated humans, rather than aliens, anyway. Enter the eponymous Madam Gkika, who IS a Jägermonster, complete with the usual elastic grin full of fangs and pointy ears, but also (usually, though not always) shown with normal human skin tones — unusual among the Jägerkin — and so, hiding in plain sight. Got all that? Good...
We later find out that Gkika can change her skin color at will. It's unknown what her natural color is.
Parodied an an early Sluggy Freelance plotline: There is a Green-Skinned Space Babe, but it turns out (s)he's the male of that species. Riff and Torg oddly don't seem to care, and continue ogling him as blatantly as before.
Aylee plays this straight when not in a draconic or serpentine form.
Subverted in The Inexplicable Adventures Of Bob. Princess Voluptua looks the part of the stereotypical alien space nymphette, right down to her skimpy one-piece outfit. However, this is an illusion; underneath it, she is a giant butterfly creature, and this is common knowledge among the cast. When designing her shapeshifted human form, Voluptua claims to have gotten the normal human female proportions wrong unintentionally; she has not corrected the error.
Outsider, because it started as a Master Of Orion fan-comic, has two of the main Loroi characters being obvious copies of the Elerian scientist and soldier.
MSF High has the true legion, planty alien chicks that can convert other people into more true legion.
Emsi of Drunk Aliens has green skin, blue hair, antennae, & a tail.
A villain in an episode of Eek! The Cat parodying Star Trek uses this exact wording to refer to his highly attractive spies.
A lampshade hanging of this occurs in Futurama, in the episode where Zapp Brannigan tricks Leela into sleeping with him. From the Captain's Log, dictated to Kif at the end of the episode:
"We have failed to uphold Brannigan's Law. However, I did make it with a hot alien babe. And in the end, is that not what man has dreamt of since first he looked up at the stars?"
Of course, the irony when you realize that Leela turns out to be a mutant human, not an alien, makes it even more hilarious.
To many women over the course of the show, Kif is the green skinned space babe.
Grandpa Max of Ben 10 married and had a family with a purple-skinned Energy Being (who hides it well), and later dated a literal Green-Skinned Space Babe.
The ultimate dream of Jamie in Megas XLR is to visit a planet full of these. He even picked up a few such girls in "Battle Royale", though it was entirely due to the money he made from betting on Coop's winning streak.
"Coop, what're you doing man? I've got digits from green-skinned girls! GREEN-SKINNED GIRLS!"
The bounty hunter in "Department of Megas Violations" is a blue-skinned one.
An episode of Stroker and Hoop deals with this. She was a secret government agent sent to kill him the whole time.
In the Tek Jansen cartoons shown on The Colbert Report, Tek is constantly having no-setup sex with various space vixens. On one occasion, the woman in question was a fleshy outgrowth from the forehead of a man-eating space anglerfish.
Teen Titans' Starfire, the resident Orange Skinned Space Babe.
An entire planet filled with them kidnap Johnny Bravo. They later dump him in favor of Mel Gibson.
The Martian Queen from Duck Dodgers. A White-Haired Pretty Girl who walks around in nothing but a golden bra thing and an almost see-through long skirt. Impressive given that, aside from eyes, she has no features on her face at all, unless seen in profile.
Wendy Garbo from Galaxy High, sort of. And while Aimee is human, she briefly colours herself blue in the pilot.
Young Justice has one Miss Martian. Turns out it's an Invoked Trope, as like in the comic she's actually a monstrous white Martian.
Star Wars: The Clone Wars is full of them. The above mentioned Twi'lek females appear in practically every other episode, often wearing very Fanservice-y outfits, even if they're not outright club dancers or slaves. The two Ms. Fanservice characters, Aayla Secura and Su Lawquane, are both Twi'leks. Then there's Ahsoka Tano, a teenage Togruta who for the first two and half seasons was running around in a tiny tubetop, Assajj Ventress who just loves to show off her legs, and Luminara Unduli and her padawan Barriss Offee, who are literally Green Skinned Space Babes (though their outfits are much more concealing). Then there's senator Chu chi a blue skinned Pantoran diplomat, and her outfits aren't bad either.