Put together by these guys:
http://www.digitaldreamdoor.com/pages/best_guitarsolo.html
Criteria: - Guitar solos are the best display of talent by these musicians. Each guitar solo was ranked mainly for
the overall quality of its composition. Originality, complexity, influence, and lasting appeal are also considered.
Here's the top 20:
1. Comfortably Numb - David Gilmour (Pink Floyd)
2. Stairway To Heaven - Jimmy Page (Led Zeppelin)
3. All Along The Watchtower - Jimi Hendrix
4. Freebird - Allen Collins (Lynyrd Skynyrd)
5. Maggot Brain - Edie Hazel (Funkadelic)
6. Texas Flood - Stevie Ray Vaughan
7. Eruption - Eddie Van Halen (Van Halen)
8. Highway Star - Ritchie Blackmore (Deep Purple)
9. Cause We've Ended As Lovers - Jeff Beck
10. Hotel California - Don Felder/Joe Walsh (Eagles)
11. Mr Crowley - Randy Rhoads (Ozzy)
12. Little Wing - Jimi Hendrix
13. Time - David Gilmour (Pink Floyd)
14. Layla - Eric Clapton/Duane Allman (Derek & The Dominos)
15. Sweet Child O' Mine - Slash (Guns N Roses)
16. Cliffs Of Dover - Eric Johnson
17. Nottingham Lace - Buckethead
18. For The Love Of God - Steve Vai
19. Voodoo Child (slight return) - Jimi Hendrix
20. November Rain - Slash (Guns N Roses)
Also have a look further down the site for 100-200 and the top 100 Live solos. Obviously there can never really be a definitive list but these seem quite well reasoned and balanced. A certain David Gilmour makes quite a few appearances too as you'd expect.