#3 Kevin Owens

Following a year of standing up to miscreants in the form of first Shane McMahon and then Seth Rollins, Kevin Owens is probably the most over babyface on RAW right now. The Prizefighter is great both on the mic and in the ring. Thus, it only makes sense that he gets a shot at the WWE Championship.
As a matter of fact, many fans expected KO to be Drew McIntyre's first challenger but he could always follow up once the Scottish Psychopath is done with Rollins. Yes, I know that Owens is currently a face and seldom does the WWE book two faces against each other. However, given just how good KO is at transitioning between personas, perhaps he could turn heel for his feud with McIntyre and turn face again – if need be – once the storyline concludes.
Did you know a top WWE Superstar just wrestled outside the company? More details HERE
There's no doubt that this battle of brain vs. brawn will give us some incredible spots, much like KO jumping from the WrestleMania logo on the announce table during the Showcase of Immortals. Rest assured, the feud would only enhance the reputation of both competitors, irrespective of who comes out on top.