When I was 14 the Marine Corp showed up at our scout camp (kind of a "get em signed up early campain" I guess), and brought along all of the good toys. I got a chance to fire their M240 full-auto machine gun, it was freaking awesome, I've wanted one since...for duck hunting.
The most powerful weapon I ever fired was an M-2 at night with tracers.
I'd love to have a WWII era version of this weapon.