They seem to have a "dark side" to their persona. Some, if not all, of their videos are weird and so were their early performances... I mean embarrassingly wierd, IMO. But I don't really pay much attention to that stuff. Lots of bands or performers feel like they need something that makes them stand out. I guess they went the "sold their souls" route or whatever.

For me its simply a non-traditional approach to music. A lot of their early music got considerable airplay on the radio. After the first album or two their music became less dark but also even less traditional. They started using more complex rhythms and writing longer songs that were not radio-friendly. I'm surprised they have any fans at all but the ones they do have seem to be willing to pay a considerable amount to see them (at least it seems like a lot to me).

One thing I don't like is their sound hasn't changed much. The music has changed a bit but their music sound hasn't very much IMO. Where some bands can play the blues, rock, etc... Tool just plays Tool, lol But they do that very well and that is my interest. And to me, I'm seeing something that is kind of rare. I can overlook the genre if the music, to me, is exceptional. So, I am seeing a band that I think is one of the best and in my top 10... For what its worth the rest of the top 10 is either dead or not performing anymore.

Led Zeppelin
AC/DC with Bon Scott
Johnny Cash
Jimi Hendrix
The Beatles
Pink Floyd (although I passed up an opportunity to see them when I was younger because Roger Waters wasn't with the group at the time but now I would no matter what)
Neil Young

Anyway, for me Tool is at the bottom of this top group.

It gets cloudier after that.

Simon and Garfunkel
Eric Clapton has to be in there somewhere in some form
The Beastie Boys
The Kinks

And I like Yes a lot but I've seen them a bunch and they don't play the songs that I like... which aren't their "hits". I like Beck a lot but not his last album and I think I would be disappointed to see him live. I would like to see a few others just based on their talent, like Chet Atkins or Stevie Wonder or Ray Charles and a bunch of others. I like Rage Against the Machine a bunch but I don't think I want to go to one of their concerts... not that they are, or would ever, tour again.