Best Rock Song Of ALL TIME?

Yeah, I know. There's no such thing, being that this kind of thing is highly subjective and all, but I believe that there are some rock songs that are not only so iconic that they embody the very heart of what rock and roll is, but transcend the genre itself to redefine what we consider it to be.

My entry: Queen - Bohemian Rhapsody

This song changed it all for me back when I was just 13 years old and heard it on the radio. Even now I learn something new each time I listen to it. I don't believe there is any song like it in the history of rock. Its genius is as evident today as it was the day it was released.

I don't consider this an argument, just an opinion. I will only contend that in order to be considered for the honor of best rock song of all time that it be a song that is more than just a catchy tune. Those are a dime a dozen in this landscape. Great songs take it to the next level. Bohemian Rhapsody does this more than any song in my opinion, but I know there are many others that fit this criteria. I'd like to hear your opinions.
If I had to choose, it will definately be an early Simon & Garfunkle, "America" ( from my all time favorite lp!) Agree with Csontos, it largly has to do with the time it was released.