#2 EC3
Those of you who know EC3 know that he was once 'Derrick Bateman' in NXT. He went to TNA and reinvented himself into Ethan Carter the Third, Dixie Carter's spoiled on-screen nephew. While in TNA, EC3 captured the World Championship twice and the Grand Championship on one occasion too.
What separates EC3 from the rest of the pack among the call-ups is that he's a fantastic promo as well, and will be a perfect fit for RAW's more 'sports entertainment' moments. He has a great physique and a certain smugness that sets him apart as a character. Oh yes, before I forget, he's no slouch in the ring either.
There are far too many superstars with similar attributes to EC3 who have not fared nearly as well in the main roster. Bobby Roode, also of TNA fame, is one of the names that comes to mind, almost at once.