"IT'S A ****ING GLOVE!" - Everyone, 2005
Master Hand is the primary villain of both Super Smash Bros. and Super Smash Bros. Melee. Really, though, he's little more than a faceless (literally!) end-boss at the conclusion of both single player adventures.
In one of the most surprising results in Contest history, MH defeated Kuja in the first round of the Spring 2005 Contest, proving once again that company fanboyism knows no bounds. (This outcome was foreshadowed in the same tournament, when Ansem defeated CATS.) After his victory over such a well-respected Final Fantasy villain it was naturally assumed that SSB had boosted Master Hand to a decent amount of strength and that he would continue to make noise in the tournament. Instead, the Hand surprised everyone once again by totally tanking against a pretty weak Dr. Robotnik, which resulted in Kuja pulling down with one of the worst X-Stat values ever seen.
In 2009, a glitch in Melee was discovered that allows players to play as everyone's favorite disembodied hand.