the only one i've enjoyed is Dolphin Olympics, but it got boring after a few hours. Especially since I went to bed with the best score in Calgary, then woke up and was like 20th in Calgary...damn nerds.
none of them, facebook apps suck, it was originally just a place to talk with friends but now it's e-mails about speed date and fucking which heroes character you are. i have 637 app invitations right now and they keep coming, too annoying