I don't really like Bacchikoi too much, the characters are a bit too cliché and the story is not great. They also behave in quite a dumb fashion, so I didn't find the game engaging enough (the supplement is just a bunch of sex scenes to cover all the possible combinations of characters, which is, ok if you want to have erotic material, but that's not a game).
Full Service has great graphics (if you like manga-style) but has a lot of unexpressed potential. The story could have been way better developed as it had intriguing premises, and it rushes to the conclusion with all the scenes in between feeling like filler just to have sex images. The game itself is also pretty badly done, flashy but without the depth, so it was a bit of a letdown for me. It's very attractive at the start because it's colorful and it seems you can do many things, but it fell short.
A good game which is more of a life management/dating sim than a story is Seiyuu Danshi. Not the most engaging but I liked it.