#4. Cesaro

Both Big E and Cesaro became full-time members of the main roster in 2012. After initially debuting as a heel, he would go on to win the US Championship in his first year on the main roster. However, he's mainly been used in the mid-card and tag team division ever since the promising start.
While he's still been able to showcase his amazing technical and athletic ability, he really hasn't been given many shots or opportunities at either the WWE or Universal Championships. His matches are usually among the best of the night, the most recent examples being his bouts with both Ricochet and Aleister Black. His 2-out-of-3 Falls match in NXT with Sami Zayn was one of the best matches in NXT history.
For whatever reason, the management just doesn't see him as a World Champion. He isn't the best on the mic, but neither is Roman Reigns. The Big Dog has already won every title in the company.
Although he may never get the chance as Kingston did, the crowd would probably go nuts if he did win a major title. His athleticism, strength and exceptional in-ring talent are routinely on display and more than justify him winning either the WWE or Universal Championship.