I'm not a big fan of sex in games. I don't have ANYTHING against sex or nudity in films and real life, but have you noticed how games with sex and nudity get higher ratings than those without? I'm pretty sure Heavy Rain and Mass Effect are good games (I KNOW God of War is a good game) but there's this nagging feeling that some people only like them because of the nudity and sex. I don't like that. I judge a game on story, gameplay, and replay value. If there's sex in it, I don't care, it's not a plus or a minus for the game. I'm not homosexual or anything, but I just don't think sex really improves a game.
Violence, however, is different. You can't preform violence in real life without penalty. If you blew up some guys head in real life, prison for life. If you explode a guys head in a video game, cool! +50 points! Video games allow us to do things we can't do in real life, like fly around, kill demons, shoot aliens, chainsaw zombies, bomb terrorists, and save the world. Sex is something to do with a real person to show you love them, not a virtual A.I for your own pleasure.