Too many names to want to pick one. I always liked the drama, good storylines, and characters over technical wrestling ability, so all the attitude era talent ranks high with me.. if I had to pick one, it would be Stone Cold Steve Austin... even moreso after watching some of his work in ECW prior to getting hired by the WWE.
Honorable mentions: Undertaker, Kane, Rock, HHH, Shawn Michaels, Mic Foley, Vince, Kurt Angle, Jericho, John Cena, CM Punk, Steve Blackman.. kind of in order from most to least. I'm sure I missed some names, these just come to mind. Good matches with tables, ladders, and chairs come to mind, hardcore matches, and some good work done by the 'mid cards' but I can't think of all their names. Dudley boys, Acolytes, Rikishi, a few midcarders I can remember that I enjoyed.
Its going to come down to peoples preference between the rock and austin
Although I know that austin had more impact on the wwe it was the rock who had me tuning in every week sp ill go with him . but if you asked me this question on another day i could say austin , thats how close it is for me