Halo 2 is almost as stupendously broken as Ocarina of Time. Superbouncing into inaccessible areas with game objectives --the skull on oddball, flags on CTF-- during live matchmaking games was fun. Sword flying (and rocket cancelling) across maps was entertaining too. As was searching for the golden warthog and banshee...

You can check out some speedruns of the game from Monopoli to see a pretty impressive number of glitches. Here's one from AGDQ 2014: http://www.youtube.com/watch?v=po9HS2lIZRw .