best non guitar rock solo

Paul Butterfield's harmonica solo on "Everything's Gonna Be Alright"
Steve Winwood's Hammond B3 Organ on Hendrix's "Voodo Child"
Violin solo at the end of The Who's "Baba O'Riley"
Opening piano solo on Elton John's "Funeral For A Friend"
Bobby Keyes' sax solo on the Rolling Stones' "Can't You Hear Me Knockin'"
Ginger Baker's drum solo on Blind Faith's "Do What You Like"

Mark Nauseef(drums, percussion, marimbas samples etc...) in his solo album Wun-Wun on CMP along with super voice performance of Jack Bruce.
Another superalbum is "Transmutation" by Praxis(one of the Bill Laswell's projects) I realy don't recall the name of the keybords master but he was faster than fusion!
And certainly everyone here should know the famous flute master Ian Anderson.
Also check out keyboards in Steely Dan not neccesarily solos and that is realy stunning even on the background!

Clarence "Big Man" Clemmons on "Jungleland" from Springsteens' "Born to Run".

From Quicksilver's Shady Grove disk.

I'll second Ncarv's "Toad" (Ginger Baker) and Rostamann's "Do What You Like" (Ginger Baker). Yes, I'm a big percussion fan ;-) Great stuff in jazz too, but that's another thread. Marakanetz, I'll have to check out Wun-wun -- I'm a big Jack Bruce fan (gotta love "Theme for an Imaginary Western" written by Bruce and performed by Mountain).