unfortunately kids these days don't know who Deep Purple are. truly a sad sad day 
Hey I'm only 18 and I know who Deep Purple is, Ritchie Blackmore is my lord and master for all time. Mk II was the greatest band to ever exist, Machine Head, Made in Japan and the 1972 live Copenhagen DVD are some of the most incredible musical pieces of history you will ever find. No guitar player has influenced me as much as Blackmore, I had started to stagnate in my playing until I picked up a copy of Machine Head, I learned from that to use scales all across the neck and that the whammy bar needs some love every once in awhile.
Pretty much any solo by Blackmore is bound to be brilliant, but to specify I'm going to say the guitar solo in Never Before is goddamned incredible. Unfortunately it is utterly outshined by Jon Lords' piano solo at the end, the most awesome keyboardist in the universe.
So, Never Before from Deep Purple, guitar and keyboard
Midnight by Joe Satriani (well anything from him, but I just love good tapping, let's face it: Van Halen was horrible at it)
The shredding at the start of "Why Does it Hurt When I Pee?" from Zappa
The bass solo from "I'm the Hell Outta Here" from Steve Vai (Billy Sheehan plays bass better than most people play guitar)
Comfortably Numb, from Floyd solely on merit of incredible tone
EDIT: Dammit I just can't keep myself from saying it. Page wasn't that good. He was incredibly sloppy and was usually too drunk to figure out what he was doing wrong. Fairly decent tone though. I just don't like people talking about him like he was some god.