Hey all,
One of my faves has always been the riff on "Life in the fast lane" by the Eagles.

I'm also a big fan of AC/DC, "Have a drink on me" was cool, and also "Hells bells".

Metallica, and Megadeth have some cool riffs too, there's no way I could narrow it down to one. It should be interesting to see the results of this poll, and what else gets mentioned here.