theres way too many to choose from, but i gotta agree 'comfortably numb' is a good one, i also love 'stairway to heaven' and some metallica songs that i cant think of at the moment
best guitar solos? its really a matter of opinion. my favorites are either "Dark Star"- Jerry Garcia (Grateful Dead) or "David Bowie"- Trey Anastasio (Phish). In terms of complication and versitility of both Jerry and Trey's guitar playing no mainstream rock'n'roll guitarist comes close. yet there are many jazz guitarists that blow all these guys out of the water. Al di Meola is simply the best. all my opinion ofcourse
Comfortably Numb Maggot Brain (Check this one out!!!) Shine On You Crazy Diamond Black Sabbath IMO JOn
The third solo an 'One' is probably their most famous. There are three great ones on 'Fade To Black', too. 'Welcome Home (Sanitarium)' has four amazing solos, but the first two are the best.
'Achilles Last Stand' by Zeppelin. Then maybe the South Saturn Delta version of 'Here He Comes (Lover Man)' by Hendrix (pretty much the whole song is a solo). And 'Good Morning Little Schoolgirl' by Ten Years After has a sick blues solo.
This is a top twenty guitar solo ever (at least.) https://www.youtube.com/watch?v=8akmP6Sjv2o Buckethead - Whitewash. Don't worry - it's not just mindless shredding. It's amazing.
Al Di Meola is very fast, but for passion and skill, Paco De Lucia and John McLaughlin are amazing. The stuff Hendrix and SRV could do with their guitars is amazing, too.
Nice too see someone mention Maggot Brain. Eddie Hazel is one of my favourite guitarists. Are you familiar with his solo album, 'Games, Dames & Guitar Thangs'? He covers songs like I Want You (She's So Heavy) and California Dreamin' ... Fabulous stuff if you ask me. Back to the subject... best is obviously subjective, so a few of my favourites are: Led Zeppelin - Since I've Been Loving You Roy Buchanan - Roy's Bluz John Mayall's Bluesbreakers - Have You Heard Cream - Sittin' On Top Of The World Jimi Hendrix - Machine Gun SRV - Texas Flood Freddie King - Have You Ever Loved A Woman Crosby, Stills, Nash & Young - Almost Cut My Hair