iPhone 4S. I loaded iOS5 on my iPad 2 a few days ago, and quite honestly I am underwhelmed. Coming from Android things like notifications and a split keyboard are ho hums. The gestures are nice. iCloud is meh. I honestly would have called it 4.6 instead of 5. To me the interface is just too dated. AND they stuck the Newstand icon in my face with no way to hide it or put it in a folder. Truth be told, the icons Apple chooses to push down my throat is really the one thing that is a turn off for me.
Other than that, its cool. 😎