Illusion Labs, and True Axis for their great games/game and also support on TA. I also like Chillingo (loving The Hero) and X2 (X2 Soccer is fun). Dislike Gameloft and Ngmoco.
I love Activision, they don't launch a lot of games for the iPhone, but when they do, the games they launch are awesome. I also like Gamevil and Com2us for their excellent RPG games. True Axis for their Awesome Jet Car Stunts. I dislike Gameloft for their lack of game support and originality and Ngmoco for an obvious reason, their Freemium System is way too Greedy in comparison of other Freemium Games, I think that they deserve a brand new title of gaming categories such as Ngmofism.