NBA 2K12 is currently the best basketball game for the iPad, though it does feel like you're playing the circa 2007 console version of the game. While it does feel a little stripped down (there's no play-calling capabilities, for example), the control scheme works pretty well, there's a full season mode, and the game grows on you as you play.
All that said, we're adding this one with a big asterisk because 2K Sports' update for iOS5 created huge graphical glitches that have caused a number of users to leave one-star reviews. Hopefully, 2K will correct this soon because it's a solid basketball otherwise. Oh, and it would be good if it lowered the price while it's at it.