Why Pangea software of course! Nanosaur? Genius! Absolutely stunning. It would've gained all award at IGF if they allowed it to compete. Damn judges and their "rules". In all seriousness, either Chillingo or Freeverse, not sure which.
Ian Marsh/NimbleBit. Why? Ever single game they've released is completely polished. And of course, are also fun.
It was tough between ngmoco and illusionlabs because they are both equal, but I chose ngmoco because they have more quantity, but the two have equal quality!
Mines Gameloft. Look, BIA, HoS, Terminator Salvation, AC (assasians creed) Those are all great quality games