Does Enigmaticman still come on? If not, then I'd go with Liber .

If Reventon were on this site anymore, then him. But he isn't, so I'll go with Libertarian1.

If there was a "Most likely to reestablish colonialism" award, you'd have my vote ;)

A recent one would be Jungleson, he's just incapable of grasping anything, even when he concedes every one of his points.

Pick and choose from the following: Liber, Ben, Libertarian1, Apollo, Reventon.

I've seen Saurbaby and BenWalters do a pretty broad range of debates over time.