A couple of years ago when I lived in a dorm at the University of North Florida, we played Halo 2 over the network all the time. My favorite way to kill someone was to come down from up top (like Batman) and I would always say "I'm Batman" like Michael Keaton in the first movie. This became my gimmick and I would go all out with it.
Throw a sticky grenade, "Got somethin' in my utility belt for ya." Ghost = Batcycle, Warthog = Batmobile; you get the idea. The guys in the dormatory thought it was pretty funny (I was the only gimmick IIRC) and always asked where I lived (you can guess my response).
Oh, Batman is also bad ass and the "R" comes from my first name, Robby. Although, I do kinda want to change my gamertag.