The best glitch I remember is when I was doing rykuta's halo tdm and he had the bases garage jammed as tightly as possible with dozens of vehicles.
I clicked on one of them, and it bumped into the one next to it, then both of them started shaking, suddenly they flew apart and through all the other vehicles, then the server froze up with lag for like ten seconds, and when the lag ended there were ten vehicles stuck in walls, half the team dead by getting run over, a couple vehicles spazzing out in midair, and the rest of the vehicles probably halfway to neptune by then.
It was glorious.
