...drum-roll... Anderson Silva, Georges St-Pierre, Jon Jones, Chael Sonnen, and Rashad Evans. A few surprises in there. Silva has traditionally not been a draw. Recent bouts with Sonnen have drawn a lot of interest but it is yet to be seen if he can continue to draw without him. Not obvious yet whether Sonnen can sell a non-title PPV on his lonesome, especially with the way he flamed out against Silva in their rematch. Evans is also a surprise. Evans vs. Jones got about 700k buys and Evans vs. Davis drew 4.7-million viewers on FOX. His bout with Rampage Jackson eclipsed 1-million buys on the back of a highly rated season of TUF. Little surprising that there are no heavyweights on the list. Junior dos Santos was able to draw nearly 9-million viewers on the inaugural FOX show vs. Cain Velasquez but his bout with Frank Mir was a typical to low drawing PPV (sub-600k). Presumably a bout with Overeem might've done better.
The only one on that list that surprises me is Rashad. Really? That's a big surprise to me...especially with how often he gets referred to as boring.