Well lets see...
Eddie Van Halen - Eruption (Van Halen, Van Halen)
Randy Roads - Crazy Train (Ozzy, Blizzard of Ozz)
Eric Clapton - Layla (Derek and the Dominos, Layla and Other Assorted Love Songs)
David Gilmour - Comfortably Numb (Pink Floyd, The Wall)
Slash - November Rain (Guns N Roses, Use Your Illusion I)
Brian May - Bohemian Rhapsody (Queen, A Night at the Opera)
Kirk Hammett - Fade to Black (Metallica, Ride the Lightning)
Kirk Hammett - Orion (Metallica, Master of Puppets)
Kirk Hammett - One (Metallica, ...And Justice For All)
Jimmy Page - Whole Lotta Love (Led Zeppelin, Led Zeppelin II)
Tony Iommi - War Pigs (Black Sabbath, Paranoid)
Donald Roeser - Don't Fear The Reaper (Blue Oyster Cult, Agents of Fortune)
Stevie Ray Vaughn - Texas Flood (Texas Flood, Texas Flood)
You know there are just way to many great ones to name. I could go on and on and on...
Not the best, but probably one of my favorites:
View: https://www.youtube.com/watch?v=gk9Um1tDAxM