Really, when it comes down to it, I could just start listing guitarists I admire in general, guys who play well in every aspect. But I'll try to specify what makes these guys top notch:
re: Pete Townshend, he just did stuff with chord voicings that hadn't been done previously in a rock context. "Pinball Wizard" still fires me up to this day.
Hmm. How 'bout Dean DeLeo of STP? Very rarely plays lead breaks, nice tight sound that always moves the song forward.
I'd have to agree re: Malcolm Young and Jerry Cantrell, too. Without Malcolm you have no AC/DC, plain and simple. And JC has it all going on with dark sounds, full chords that still come through well even though distorted out to here.
And Nuno Bettencourt. Fiendish player. He really blurs the boundary between rhythm and lead, which is great. Plus his songwriting is top-notch.
Here's a big "hell yeah" for Alex Lifeson. He plays with so much range, tonally and stylistically, that it's staggering. One of my first guitar heroes back in the day.
Okay, enough for now.