Like these, probably the two best AMVs of all-time!
FLCL edited to Wilco's "Jesus Etc."
Akira edited to U2's "Sunday Bloody Sunday"
In my case, AMVs could be attributed to helping me in my subsequent anime/manga selections which would probably seem counterintuitive to the true AMV fan. Thus, AMVs could be, on a small level, like a commercial for the manga made, unknowingly, by the fans. So, the types of songs the fans synch up to the anime have unintentional target audiences.
After reading the 16th volume in the Dragonball series, I dove headfirst into the world of Dragonball(Z) on YouTube. Dragonball Z seems to have a more diverse fanbase than most animes. This was apparent when I found many AMVs set to rap singles in addition to the typical Linkin Park and Orgy songs. Some of them were really popular singles I would have expected had I even expected to find rap used in AMVs, but others were slightly less popular songs that I'd have no reason to assume were being used in AMVs.
Conclusion: DMZ's fan base is partially made up of secretly nerdy rap fans.
Here are a few of the worth-watching gems I found:
Soulja Boy- "Crank That"
M.O.P.- "Ante Up"
DJ Felli Fel featuring P.Diddy, Akon, Ludacris & Lil Jon- "Get Buck in Here"
Lil Wayne- "I Feel Like Dying"
T-Pain featuring Yung Joc- "Buy U A Drank (Shawty Snappin')"
DJ Khaled ft. R. Kelly, T-Pain, Lil Kim, Young Jeezy- "We Takin' Over remix"