Greatest Rock Guitar Riffs

Too much time on my hands -- so many great ones spring to mind, including some that have already been mentioned:

"Kashmir" by Led Zeppelin
"Statesboro Blues" by Allman Bros. Band (or Taj Mahal)
"Paperback Writer" by The Beatles
"Start Me Up" or "Brown Sugar" by The Rolling Stones
"Roundabout" by Yes
"Juke Box Music" by The Kinks
"Tush" by ZZ Top
"Baba O'Reilly" by The Who
"All Along The Watchtower" and about a dozen others by Jimi Hendrix (AATW is no longer a Dylan song, IMHO)
"Mysterious Ways" by U2
"Layla" and "Crossroads" by Clapton (and others)
"Supernatural Superserious" by REM
"Yellow Ledbetter" by Pearl Jam
"Smells Like Teen Spirit" by Nirvana
"Cinammon Girl" by Neil Young
"Walk Away" and "Rocky Mountain High" by Joe Walsh
"Volunteers" by Jeffereson Airplane
"Long Time Gone" by Crosby, Stills and Nash
"One More Saturday Night" by The Grateful Dead
"Love Me Two Times" by The Doors
"Sultans of Swing" by Dire Straights
"Sweet Home Alabama" by Lynyrd Skynyrd
"Fortunate Sun" by Creedence Clearwater Revival
"Maybelline" by Chuck Berry
"Rave On" by Buddy Holly

And on and on and on...

Happy listening!

Eric Clapton, "Eyesight to The Blind", from the rock movie "Tommy".

"Lateralis" - Tool
"25 or 6 to 4" - Chicago
"Hey You" - Pink Floyd
"All Apologies" - Nirvana
"Kashmir" - Led Zeppelin
"Here Comes the Sun" - The Beatles
"Voodoo Child (reprise)" - Jimmi Hendrix
"Enter the Sandman" - Metallica

Hendrix Star Spangled Banner! Just the first six chords are enough to last a life time.

Metallica - Master of Puppets
Iron Maiden - Wasted Years
Deep Purple - Perfect Strangers

just to mention a few awesome ones.