I do enjoy them, I must admit. Yeah, I'll admit that I'm a pervert, so there's that side of them that I enjoy. But I tend to pick ones that sound like they have a decent story as well. If they don't sound like they have a good story then I'll usually pass on them.
Kana ~ Little Sister is a superb game, and so far is my favorite. Heat de Roommate is rather amusing, though.