Just as a nitpick, but Teal’c from Stargate-SG1 (your second example) is human. The Jaffa and the other slaves of the Gouald are the descendants of worshippers of the Goauld who fled with/were taken by the Goauld from earth when the rest of humanity realized the Goauld weren’t gods and rebelled against them.
Really hard to say exactly what would be acceptable since we have never really encountered an extraterrestrial life form. That is public knowledge anyway. (Nod to the conspiracy theorists.)
About all I can do at this point is run out a list of probable disqualifiers, most of them rather obvious.
First off, just about anything with a significant size difference. Nothing on the order of Jabba the Hut even if it does look like Jolene Blalock. Same for being too small.
Ambient body temperature needs to be close to 98.6. Something who’s norrmal temp is 75 or 110 would be far too uncomfortable.
Hazardous mating rituals can be a deal breaker, but not necessarily.
Chitin is pretty much out. I like to cuddle and I just don’t see it working.
Tab A and slot B design is important.
Being able to satisfy the partner is also important. Tab A and slot B might work for me, but if I have to be able to apply 500lbs of pressure to a point to crack an endorphin filled cavity in J’hkkkt’r for ‘her’ to achieve orgasm, she’s going to be disappointed.
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Not a problem. Just get a red sun powered solar vibrator and we’re in business! How ya doin’ Power Girl?
Who’s the brunettes, and who’s the blonde applying for the Legion (Supergirl?)?
Cir-El, Laurel Kent, and Laurel Gand.
Won’t help you with Linda Danvers, who is the cutest of the bunch. And Supergirl
Prairie squid can be used safely if first debeaked.
Not to mention that they’ve been rigged so that the shells of the eggs require the saliva of Cirocco Jones to become permiable to sperm. It’s a really odd form of population control.
I forget the name of the baby that was born with similar saliva.
As to aliens: + sense of humor
- causes nasty rash
Our form of foreplay may be dangerous to you.
Spoilsport! 
Trek did do a bit of hand-waving around that, blaming the over-abundance of bipedal, humanoid, carbon-based life forms on an earlier race spreading their DNA around and influencing the development of many younger races.
From memory the aliens were all female, reproduced by parthenogenesis, and were related in an evolutionary way to the indigenous population of the planet (called “Wogglebugs” in the story?). They had the ability to alter the morphology of their off-spring by imprinting on their mate… their reproductive strategy being to mate with a male Wogglebug (while posing as a female Wogglebug), then leaving the male to raise genetic “cuckoos” (of a sort). I can’t recall how the female in the story had come to look human (as did her litter-sisters), but while she was able to pass both cursory and intimate examination as a human her inner workings remained very alien.
Actually, the Titanides each have THREE sets of genitals. They ALL have rear vaginas and rear penis, with only the set between the forelegs being either male or female but not both. They can all get pregnant, they can all inseminate, and those with two female sets can clone themselves, a mode called “aeolian solo”.
As for the OP - well, the Horta are definitely out. Not sure where I’d draw the line, to be honest, but I suspect I’d be pretty prudish since I won’t have sex with half my own species, much less anything outside of it.
Any woman would put up with it all to hit this!
Unless, of course, it were the size of, say, a gerbil . . .
That may be, but taking one of those lovely lasses over the top would likely result in muscle spasms that would pinch something important off. :eek:
I want a Bene Gesserit Concubine.
That character, however, isn’t an alien, just an evolved descendant of ordinary cats.
ETA: Sadly, I guess that would also disqualify C’Mell.
We can’t be the only people who think about this stuff. If other intelligent species exist elsewhere in the universe, and if we ever encounter any, there’ll be some human who thinks, “I’d hit that. Say, would you call those ‘legs’ or ‘mandibles’?”
I think there’s a website for that.
I mean, I’ve heard…
Wow.
That’s…
Wow.
I’ll be in muh bunk.