As many as there are yaoi/shonen mangas around, there aren't much Boy's Love games to get by to. So, if you've got one in mind, happily share it to everyone in this thread. You'd make many fanatics out there happy. I know, I'm one of them. ^_^
Mostly popular is the well-drawn Silver Chaos with it's continuation, Silver Chaos2. A good advise is to download the whole CG or pix collection rather than the game itself, but where's the fun in that?
Other than that is Enzai, Angel's Feather, and Absolute Obedience in which I've never had the chance to try out. Although most of them are in Japanese text, what's the harm in looking at those wonderful scenes?