Avatar for me as well. At our launch party I almost flipped it over it made me so mad. Now, after 100's of plays in league, it is a solid 6 or 7 for me. Really a fun game with some great MB's. We do still call it Avaturd for some reason.
Next would be TWD. Again, at our launch party pretty much everyone despised it. Now with better code and some more time on the game, most of our league players like it OK. For some reason, we do still refer to this one as The Walking Dud!