People normaly hate AMVs, they are repetitive and boring... allways the same thing.
But many animes got some really good AMVs, some of them dont have the popularity they diserver, and Dragon Ball got some really good ones, if you know a good DB/DBZ/DBGT AMV just post it and share it with everyone.
Here are the best AMVs I've found:
Goku vs Majin vegeta:
DBZ in 10 minutes:
Legend of the Sayan race:
Battle aganist Omega Shenron (this battle was boring but this video makes it look epic!):