I have seen quite a few sites about this actually (thank you StumbleUpon for being so suggestive), but this one I think is the best one out there. It’s not the biggest collection, or even the quickest of sites, but I really love the commentary on the games.
I have actually played quite a few of those games, but never really noticed any of these things. And there are of course games like Cho Aniki (image above) that are truly very disturbing. But there are quite a lot of really funny games and sexual situations there as well. Teenage Mutant Ninja Turtles, Rampage, Battletoads, Power Instinct and Rings of Power come to mind.