Solo(s): Goodness...Theres just sooo many!
Pink Floyd - Time/Comfortably Numb
Derek Trucks Band - Revolution
And any solo done in a Tenacious D song. Jokingly (is that a word?) or not Kyle rips nasty rock solos like its his job....hey, I think it is.

Riff(s):
Opening to Voodoo Child (Slight Return)...never fails to amaze.
Hendrix - Spanish Castle Magic
Derek Trucks Band - Volunteered Slavery :D (My idol)