I have never met too many Tool fans (Tool were never that big in the uk).
From my experience Radiohead fans are cider drinking studenty arsefuckers. Oasis fans, vile louts. Axl fans, deluded to the point of insanity. With Zep fans, I find them to be too smug about their band and full of statements like, ''Zep are the greatest band ever ever and all other bands are crap'' or something like that. By the way, I like Oasis - and, obviously Axl - and to a limited degree, Radiohead. This is solely based on observing their fanbases.
Fans I like? Elvis fans. They are a bit mad. Mad in the same way as those people who collect Royale memorabilia (cups with the Queen's face on etc). But they are usually great people. Beatles fans are great (I am one) but perhaps they can sometimes come across as smug in the way Zep fans are about their band's greatness. Dylan and Neil Young fans are anorakish in the extreme. Gratefull Dead fans also. These people have, on average, six thousand bootlegs. I like that about them actually as I am bit of a nerd myself.
What about Michael Jackson fans?