Lolzors and Chuzlife definitely don't deserve this. After scrolling around a bit on the all time leaderboard, I'd probably give it to Axmeister or Srom. Although, for the former, I don't see him on nearly as much then when I first joined, and for the latter, I don't see him debating religion NEARLY as much, so... Srom, I guess.
Okay... I haven't nominated anything, but I'm just doing to leave this here. :p