#3 Seth Rollins
While his Shield brothers are already Grand Slam Champions, Seth Rollins finds himself just one Championship short of becoming on par with Roman Reigns and Dean Ambrose.
Seth Rollins is one of the most important Superstars on the WWE roster and is destined to carry the company into the future.
Seth Rollins' Championship stats in the WWE:
Championships Won:
1) WWE/Raw Tag Team Championship (3 times)
2) The United States Championship (1 time)
3) WWE World Heavyweight Championship (2 times)
Championship required for a Grand Slam:
1) The Intercontinental Championship
Rollins might achieve this feat sooner than later, as he is ready to claim the Intercontinental Championship when he faces The Miz and Finn Balor in a Triple Threat match at WrestleMania 34.