#5 Kane
Late career Kane has been relegated to such an extent that perhaps it is best that he never closed Mania. Of course, many fans, considering the way Kane debuted and wreaked regular havoc in the Attitude Era, might be appalled that he was allowed to fall like he has.
At times, the Big Red Machine was a force that was captivating to watch, and looking at how comparable figures at the time would main event (multiple times) at some point or another in their careers, Kane is a very notable exception.
If the WWE could work Big Show, Mick Foley, Chris Jericho, Kurt Angle, Brock Lesnar, Chris Benoit, Batista, Edge, the Miz and Triple H (six times!) all into the closer, it seems to lean towards lazy booking of a truly well known character, that Kane is omitted from this group.