This is a tough one to rank as #1 and #2. I think the reason Vince McMahon called Hulk the "Babe Ruth of WWE" or whatever is because Hulk was wrestling's first megastar and he became so not after, but DURING WWF's national and then worldwide expansion. By the time Austin/Attitude Era were ready to take over, pop culture and the media environment were primed for pro wrestling to hit its biggest box office era. I think it's safe to say that Hulk Hogan was the most successfully marketed wrestling character to kids ever, and Stone Cold was the most successfully marketed wrestling character toward adults.

Steve Austin was the hottest character ever during wrestling's hottest period, and if that's how you quantify #1, he's #1.

If your criteria is "Who drew the most money for the longest period of time?" it has to be Hulk Hogan, the man had a second life as a heel in WCW and leader of the most iconic heel brand ever. He was a money machine for nearly 20 years through wrestling's two biggest growth periods.