Best rock song of all time? JUST 1! Go!

I think I have to go with Santana Europa...

Best technically constructed song ever? easier... Duel of the Jester and the Tyrant <-- Return to Forever.
Neither are "ROCK" songs but two of my all time favorites!!! Chick & Stanley really trade off on that one.

For pure Rock tune, Tosca already took "All Right Now", so now I can't decide between "Old Time Rock & Roll" or "You Shook Me All Night Long".