I'm about a third of the way through the first Mass Effect and I'm enjoying it so far. Might as well make this week's Trope-tastic Thursday somewhat relevant!
Trope: (Green-Skinned) Space Babe
Description: The attractive alien with mostly human features so having sex with her (or sometimes him) isn't too squicky. While the fictional aliens of yore were mostly green, these days the space babes can come in every color of the rainbow. Female space babes are more prevalent than the males, and they will frequently be large-chested and/or scantily clad.
Examples: Liara (and the Asari in general) from Mass Effect, Jabba the Hutt's slave girls in Return of the Jedi, the trio of male aliens in Earth Girls are Easy
Pros: After a certain point, I guess there's only so many sexual adventures you can have with humans. Relationships with fictional species can also add a slew of other compelling issues - an element of danger/the unknown, social repercussions, concerns about reproducing, etc. The flip side of that is the possibility for creating qualities and abilities that can, um, enhance the experience for the human.
Cons: Everyone's got their preferences when it comes to romance, and for many people, interspecies sex is a no-no. If you're not a fan of what can seem like unnecessary drama, pretend I copied and pasted that list of "compelling issues" in this category. Also, while they're supposed to be similar to humans, I just can't help but think that that green skin would feel a little...reptilian?
Would/Did I Use It?: I've thought about it, actually. In addition to the StS sequel, I've also been working here and there on another project, and I was very tempted to make one of the love interests an alien. I ultimately decided, however, to keep them both human. While I can understand why it's appealing for some people, the idea of sex with aliens, no matter how attractive they may be, just doesn't do anything for me.