#4 Titus O'Neil
Titus is a well-built retired athlete who looked to be poised for big things in the WWE. He formed an entertaining team, the Prime Time Players, with Darren Young. His popularity peaked when he won the 2015 MEGA Dad Award for "Celebrity Dad of the Year". He was all over the social media and WWE could have used it to their advantage.
Although he did have a short reign as one-half of the WWE Tag Team champions, it was all downhill for Titus when he received a suspension for being 'playful' with the boss, Vince McMahon. This was eventually followed by a heel turn and a losing streak. He now heads a stable called 'Titus Worldwide' which includes Apollo Crews, Akira Tozawa and perhaps Dana Brooke.
Titus is still in a good shape and certainly has a few more years of wrestling left in him. He should make a move to promotions where he can achieve the heights he deserves before calling it a career. His popularity as a nice guy is sure to bring attention to any promotion he joins.