Enjoy Sudoku (really addicted to this one)
Drag Racing
Plume (twitter app)
Pocket Casts
Dolphin Mini
Big Game Fishing
Game Dev Story
Agile Lock (haven't set up for my SGS2 yet but enjoyed it on the Photon)
I have a handful of other games i like to play a lot as well. I'm a fan of this thread since I'm always looking for that app that I didn't know I needed.