The game that I owned w/ the most glitches would have to be True Crime: Streets of L.A., for the Gamecube. Every now and then, when I would drive to a "mission", my car would drive straight into the ground, and I would get a message that said "Welcome to NOWHERE!" The game would proceed to run at about 4 fps, and finally it would freeze. A reset of the system would cure the problem.

BTW, first post here!