EonBlue

Way too many choices for this question. Deep Purple, Led Zeppelin, Black Sabbath and The Who are obvious front-runners but how about some of these:

Limelight - Rush
The Spirit of Radio - Rush

Rusty Cage - Soundgarden
Oushined - Soundgarden
Spoonman - Soundgarden
My Wave - Soundgarden

No One Knows - Queens of the Stoneage

Clean My Wounds - Corrosion of Conformity

Or how about the songs that created the genre:

You Really Got Me
All Day and All of the Night