#2 WWE Hall of Famer Eddie Guerrero
During his WWE career, Eddie Guerrero was a complete pro-wrestler. He could grapple and engage in a bout of technical wrestling as easily as he could thrill the audience with his remarkable high-flying skills. His magnetism was undeniable. He would be cheered as a loved face, and his creative villainous procedures would make the spectators applaud further.
Guerrero never managed to main-event WrestleMania, although he was treated as a fairly big deal by WWE. If not for his premature death, his fans could very well have seen him headlining WrestleMania, but fate provided the fans with a mere moment: emotional at the time and exceedingly haunting today.
#1 Former WWE Champion Kane
His dreaded wicked dentist days aside, Kane has unfailingly found success in WWE, and has always been positioned as part of the most memorable feuds. However, he has strangely never been a WrestleMania headliner.
His kayfabe brother, The Undertaker, managed to collect a couple of main events, but Kane's numerous contests on the grandest stage have never touched the top.
The man behind the character is currently the mayor of Knox Country, Tennessee, and it's highly improbable that The Devil's Favorite Demon will return for a full-time run again. Even if he returns, he won't get the opening to headline WrestleMania at the age of 54.