First thing that comes to mind, and refuses to leave, is the wonderful flying guitar solo on "Shine on You Crazy Diamond" -- I forget if it's in the first parts or the second parts -- where he's playing absolutely at the top of the fretboard, just a couple of bars before it breaks into the lyrics, and he runs up to the highest note, then falls back down playing two notes at a time. Shivers.Oh, and the walk-down in "32-20 Blues" as played by Robert Johnson.
And the lightning-fast hammer-ons and pull-offs at the end of Sultans of Swing.
Alex