Riffs:
1. Iron Man - Tony Iommi
2. Enter Sandman - James Hetfield (maybe the catchiest rock riff ever)
3. Black Dog - Jimmy Page
4. Purple Haze - Jimi Hendrix
5. Foxy Lady - Jimi Hendrix
6. The Mirror - John Petrucci (never before did only one damn chord sound so heavy)
7. Sad But True - James Hetfield (Dun!! Dun-dun. Dit-do-dit-do-dit-do dun! dun-dun!!)
8. Tornado of Souls - Dave Mustaine
9. Symphony of Destruction - Dave Mustaine
10. Damien - Criss Oliva (from the '93 Savatage album, "Edge of Thorns", the late Criss Oliva's last album)
11. Crazy Train - Randy Rhoads
12. Raining Blood - Jeff Hanneman and Kerry King
13. Cowboys from Hell - Dimebag Darrell
14. Cemetary Gates - Dimebag Darrell
15. Walk - Dimebag Darrell
16. Regular People (conceit) - Dimebag Darrell
Yeah, Darrell was a riff machine. I loved his stuff. Word is Damageplan is coming out with a new album; Dime recorded all his parts before he was killed. It's going to be an interesting record to listen to, that's for sure.
Licks
(not necessarily a solo, but a lead or harmony line, nonetheless):
1. The Trooper - Dave Murray & Adrian Smith
2. Summer Song - Joe Satriani
3. Surfing with the Alien - Joe Satriani
4. Flying in a Blue Dream - Joe Satriani
5. War - Joe Satriani
6. For the Love of God - Steve Vai
7. Lifting Shadows off a Dream - John Petrucci (the echoing clean guitar part is amazing)
8. Cliffs of Dover - Eric Johnson
9. Sweet Child O' Mine - Slash
Phew, that's all I can think of for now.