Kanye West made a total fool of himself at the MTV music awards when he took the microphone away from Taylor Swift to announce that Beyonce should have won. He undoubtedly was upset because he himself didn't win (again).
In 2006 he threw a tantrum backstage because (drum roll) he didn't win.
Beyonce showed some class by calling Taylor out to the stage to share her moment.
Here are Kanye's sore loser remarks in 2006.