This is a hard one... of course I can't just pick one... and I will certainly think of more as the day goes by... but...

Riffs: Master of Puppets (Metallica), Cowboys From Hell (Pantera), Taylor (Jack Johnson), Symphony of Destruction (Megadeth), Mary had a Little Lamb (Stevie Ray Vaughan), Money (Pink Floyd), and a lot of newer stuff from Chevelle, Breaking Benjamin, and 10 Years...

Solos: One (Metallica), anything by Stevie Ray, Covered in Rain (John Mayer), Losin' Your Mind (Zakk Wyldes Pride and Glory), November Rain (G&R), the list could go on and on... can't choose one.