Judicial Power
X2U
Sorcery
Play Judicial Power only during a DCI-sanctioned tournament.
Target opponent calls the DCI tournament judge to the table X times. If that player doesn't recieve an unsporting conduct penalty for annoying the judge, that player loses the game. Otherwise, that player loses the match.
Old Mike Long Joke
3U
Sorcery
Old Mike Long Joke can't be countered or removed from a deck by a judge.
Remove Old Mike Long Joke from the game. At the beginning of the next game of the match, search your deck for a card and hide that card in your lap. Then shuffle your deck. When your opponent isn't looking at the table, put that card into play. (Before the game, decks aren't libraries yet.)
Of course, there's always the totally broken card:
[Player name], the Terminator
UBR
Creature - Enforcer 0/1
Tap: Destroy target player. It can't be regenerated. You gain ownership of his or her cards. At end of turn, you win the game.
I know, I'm insane.