"This is not The Greatest Song in the World (this is just a tribute)"

Every labor day weekend, KLOS 95.5 had (I don't know if they still do) a countdown of the 500 greatest "Classic" Rock songs. Although the order sometimes varied, the top three were inevitably:
Led Zeppelin- Stairway to Heaven
Pink Floyd - Comfortably Numb
Lynyrd Skynyrd - Free Bird

I don't know man. No doubt these are three great songs...but the best? I mean, have you ever put Stairway on at a party? Talk about buzzkill. Same goes for comfortably numb. Freebird is a little more upbeat, but have you noticed how the last 5minutes of the song is like the same repetitive guitar solo?
How do you judge that sort of thing? Shouldn't a great Rock song be one you can listen to anytime and not just when you're "in the mood"?

There are those that say that Dylan's like a Rolling Stone is the greatest Rock song ever written. One dude even wrote a book about that one song. But the thing with Dylan is that you either love him or you can't stand his voice.

This post is not going to attempt to name the greatest Rock song, by the way, so don't get hopes up. I will enter some suggestions that might be better than the KLOS big three.
Magic Carpet Ride- Steppenwolf
We rocked this song at 12am at a new years eve party once. And the room fuckin exploded. Its just a kick ass Rock song that you don't have to be sad or happy to listen to, it just rocks.
Fortunate Son- CCR
I know you're saying this song is way played out in movies and on the Radio..BUT. Consider the theme of the song and how appropriate it was (and now is) to the Vietnam era. Its a populist song about how the poor are sent to fight. Now that I think of it System of a Down BYOB is a direct descendant of Fortunate Son.
Voodoo Chile - Jimi Hendrix
Have you ever listened closely to the opening of this song. It starts out soft with this funky guitar riff. It slowly adds this little symbol rattle. Then come the...What do you call those shaker things?...I don't know. But then whole things just blows up. Listen to it on headphones once and hear how Jimi's guitar wanders from one headphone to the other. The lyrics are simple and wierd, but then there's that one line..."If I don't see you no more in this world/ I'll meet you in the next one/ and don't be late.

Anyway, those are just suggestions. Let me hear your suggestions for the greatest Rock songs of all time. And they don't have to be classic Rock. They just have to be good.