Vorph
Silver Baronet of the Realm
Platformers, anything first or third person that doesn't require fine aiming or that has forced mouse acceleration/smoothing (UE3 games are always the worst for that) and anything with driving. For a game like Saints Row or GTA I'll play with the gamepad on my lap, switching to it when I get in a car, then back when I am on foot and need to start shooting). Other than that, a few random games which I just think the gamepad interface is much more convenient to use--XCOM comes to mind immediately there.