I voted 'Other' for FFT's instant JP Max glitch. It doesn't work for all jobs, but the ones it does work for are some of the most powerful kind.

None-the-less, though, if there's a glitch in a game, and I know about it, you can bet I'll be exploiting it for my benefit. If the game designers didn't feel like testing it for all bugs and fixing them, then I feel like I should make them regret it .