I'd like Kane, Booker, Jericho, or RVD to go over.
HHH annoys me.
Michaels can't compete regularly, I don't believe.
Now...Kane, if given the chance, could perform well enough. And his last "top belt" reign only lasted one day.
Booker T has championship experience...mostly. He was a 5 Time WCW Champion, so he could carry that belt.
Jericho never got a real chance to show off his stuff as Undisputed Champion, so if he won the world title, it'd be another good test.
And RVD, as the most over guy, would be the fan favorite. PLus, even in ECW, everyone was hoping for him to win the World TItle.