R1

The feeling of connection between a simple button press and the characters and world of the game in Ico was legendary. Off the top of my head, aside from Shadow of the Colossus, Brothers A Tale Of Two Sons has come the closest to reaching that same level of connection. The free run button in Assassin's Creed felt great, until you'd climbed up a few too many bannisters than you'd wanted to.

Any other favourite 'button presses' in games?