I think Hogan and Austin's achievements are too close to call.
I honestly think Austin deserves to be no.1 on the basis that he took WWE through their "greatest" period and up against their toughest competition they'll ever likely face... but no one could argue if Hogan gets it.
They'll be 1 & 2 and i'd imagine that Bret, Flair, Taker & HBK would probally make up the top 6