Hey Seeitall...... You are right about TOOL, they are this generations answer to Pink Floyd in my opinion anyway. As far as guitarist I agree with Stevie Ray Vaughn, also have to add George Lynch, Zack Wylde, and of course Jimi Hendrix, without Hendrix the history of guitarists would be completely different. Eddie Van Halen gets an honorable mention. Also, my friend Terry, previously of Alien Ant Farm, can play a blues guitar like it's nobody's business.
High fives to Pleasuredome for mentioning Iron Madien. Everything I know about world history came from listening to The Maidens :)