Although I know the M3 is a better car in numerous aspects, I would walk past it in a heartbeat for the C63 AMG. The noise the AMG makes could erupt Yellowstone and is simply unrivaled! I just love the oversteery, sideways lunacy the AMG offers and the straight line speed will leave the dignified M3 in a cloud of smoke!
I even hate the C-Class and love the 3 Series to bits! The C63 AMG is that good.