I fell through the city of Forli in Assassin's Creed II and had to swim around under it for a while until I could find my way back to solid ground.

Skyrim I fell off a dragon and fell and got hung on something in mid air lol!!! If you would have seen what he looked like you would have laughed.

I don't find glitches to be funny.  They usually happen to me at the worse time and forcing me to restart the game or the whole damn system.  There were a couple times a forced restart lead to corrupted data and my saves were gone.  Glitches annoy the hell out of me.

Halo 2. At the last level, I glitched a ghost through the ceiling of the cave and straight into the final battle. Best. Glitch. Ever.

WCW vs. NWO Revenge easily wins on this one. In that game, using the GameShark, you could bring the half-finished version of Wrath into the game as a permanent addition to the roster. In large part, he works flawlessly - his model is accurate and I'm assuming his movesets were accurate too... except for the one that glitches.

If you get a guy on the floor nd perform the lion tamer, well, let's just say that it glitches and suddenly Wrath is using the ring as his personal bedroom. See the following video at 1:50.

whoah. 

In Just Cause, when I smashed into a motorcycle with a truck, the character on the bike ended up in the bed of the truck and I drove him around. He couldn't get off.

After one of the updates on Borderlands 2, some weird stuff would happen. The funniest was  there were a pack of skag ( kind of like wolves, only mean & ugly) near the Happy Pig Motel suddenly took off into the air in formation, flew a little ways then landed and went on with their normal routine.

I have experienced the horse glitch in Red Dead Redemption, and damn near pissed myself. See the video for an example!

that one floor fall thru glitch in the original Jet Grind Radio on the Dreamcast. it happens at 1:22

What? stop looking at me like that!