It has to be triple h. Pre evolution was better than evolution and post evolution combined. Either him or Shawn Michaels... Really any time, like when he was doing stuff like kicking Bret Hart's chin when he was in that wheel chair (one of the most memorable moments that I've seen)
Following that I'd have to give some thought to Hollywood Rock, which had outstanding moments, and the Right to Censor, who i actually totally hated, which is what heels are supposed to do, make you hate them.
Current would be..... Sandow i guess, or Heel R-truth, if that counts.
~Three Said That~