Dave Murray is surely one of the best guitarists I've ever heard, and this song is almost 9:00 of amazing guitar work with one of the most amazing guitar solo's I know. Plus it's even better live which cannot be a bad thing .
"I'm Gonna Kick Your Ass"
I wanna kick your ass until your head falls off
Then I'll kick your head and kick your ass again
Why, I don't think it got the message
Open the door sucker, it's Zeo
Here to kick your ass
your ass
There is no one best song, so I'll categorize them by best instrumentation:
Vocals: King Without a Crown [Live] - Matisyahu
Piano: One Angry Dwarf and 200 Solemn Faces - Ben Folds Five
Bass: Tommy the Cat [Live] - Primus
Drums: Moby Dick [Live] - Led Zeppelin
Guitar: You Enjoy Myself [Live] - Phish ...25 minutes of pure improvisatory greatness