1. DIY makeouts (The Sims 2 - 2004 - PC)
The Sims 2 isn't just one of the most popular games in history - it's also considered one of the most family-friendly. Hell, our mothers play this game. So when you think "The Sims," you probably don't think "hot lesbian kissing." But you're wrong.
See, The Sims already has a pretty creepy premise, what with the player creating little people and then ruthlessly micromanaging every aspect of their lives like some barking overlord. It gets slightly creepier - or sexier, if voyeurism is your bag - when you discover that you can make your digital pets get it on, more or less, with whomever you want them to.
Make your own: The game doesn't get any more risqué than this, but really, does it need to?
They might not have the infamy of Fear Effect 2's heroines or the nudity of Magna Cum Laude's cartoon lesbians, but when you make two girls kiss in The Sims, they are seriously into it. And if you've prodded them for a while to make them fall in love, their enthusiasm is definitely gratifying. Add the ability to create and customize your dream girls, view their intense make-outs from any angle and buy them furniture and matching outfits, and America's favorite computer game skirts dangerously close to being its most depraved - as well as its hottest.