The only acceptable answers to this question are Hogan, Austin, and Rock.
Hogan was THE face of the industry from the mid-80s til about 1990, came to Flair's company and took HIS belt (took Flair almost 2 years to get it back), then started another boom when the nWo took off
Austin pretty much saved the WWF from disaster when he got on top....and people got behind his character because they was fed up with they bosses and wanted to do to them what Austin was doing to McMahon. Austin coulda had a better crossover impact, but I dont think he wanted it (Dude was offered his own show on CBS, a spinoff of Nash Bridges)
Rocky in terms of becoming a star in the business had it worse than the three (Hogan was Hogan, Austin was Kliq-endorsed, while Shawn and them was jealous of Rock), but rose above all that by becoming a star faster than the other two. Rocky was THE superstar in the industry in 2000, and unlilke Hogan and Austin, you dont hear about him refusing to do a job or working with someone else. Also, his Hollywood impact is arguably better than the other two.
I dont know if I could put Flair in the discussion. Yes, he had the longer run on top, but most of that was during the territory years (even though you could see him every Sat. night at 6:05 on TBS)