@Soriku
http://www.trsrockin.com/glitchcity.html
Some pictures and an explanation of Glitch City here.

thought of another good one, -1 level in super mario bros, and little fire mario in super mario bros. super mario bros is actually loaded with fun glitches

Actually, if anyone ever played metroid 2, that had an AWESOME glitch.

Run back and forth mashing select (or while you're falling) and it basically creates random holes in the ground and wall, etc.

There's extra areas, extra energy tanks, glitched-looking metroids, and other stuff.

As a kid, this was terrifying, as was the entire game of metroid 2.

@Soriku
I think it was this random gohst thing that was not in the pokedex and was called missingNo. (Missing Number), or called ????. Think I saw it once...

I will return tomorrow, hopfully early if I have no school

(Come on another Storm!!!)

Yeah didn't it creat 99 duplicates of whatever item no.6 was in your inventory?

How about Big Rigs: Over the Road Racing? Wasn't that whole game a glitch?

How about the Arwings in Ocarina of Time? That's the best glitch ever, nothing can ever compare.

Does anyone remember the wall-walking glitch in Link's Awakening (Gameboy)? I think if you hit "Select" right as you were walking from one screen to another, you would leap to the same spot on the next screen. This could be used to warp yourself into walls, and you could walk on the ceiling from dungeon to dungeon. It was really creepy and weird...

Has anyone else seen the "wormhole" glitch in Burnout Revenge for PS2? the bottom parameter just randomly disappears and it looks like your car is falling through a white featureless enviroment. Then you reappear exactly where you were when the glitch happened and going 0 mph. It's really funny when it happens to your opponent in split-screen, but it sucks when you are neck and neck 100 feet from the finish line...

@ topcat 8, i agree glitch city scares me 2...