RickJay got it right!
My personal favorite is AWSoP.
Baby Jane by Lou Reed
Do you mean “Sweet Jane”? If so, which recording?
First of all, I am disgusted with a guy whose handle is Elvis not taking major umbrage at anyone who doesn’t choose and Elvis song as the best classic song. 
Next, I have always had a problem with this song - is it “Sweet Jane” or “Baby Jane”?? I thought of both when I typed it. :confused :wally - I am a confused putz.
I have a live version that goes on for about 20 minutes or so and it almost never repeats itself - the licks are the best of classic rock and yet extremely original - it’s a perfect piece of rock music. The Mozart of Rock. We’ll leave Elvis as The King.
Bob Seger’s “Against the Wind”
Bruce Springsteen and the E St. Band’s “Thunder Road”
By definition, I excluded Elvis on the grounds that he falls into the category of “oldies” and not “classic rock”. Believe you me, if I thought I could pick the King, “Suspicious Minds” would be right up there.
The live version is from “Rock and Roll Animal”. It is awesome. It’s actually listed as “Intro/Sweet Jane”–that long guitar-based section at the beginning being the sort of “overture” to Uncle Lou’s show at the time.
How did the seventies ever become known as the “joke decade”? Ok, it’s the fashions, I suppose, but I’m starting to believe it was one of the most culturally consequential decades of all time. Almost all the choices for best classic song in this thread come from then. The music seems to be so enduring and important. I go swimming about once a week at the local pool. For years, though, the thought has crossed my mind as I leave to go that rather than going swimming I’m going back in time. The music at that pool is always 70s stuff. Always. Dire Straits, Supertramp, John Cougar Mellancamp, The Knack. What about the Eighties? What about Psychedelic Furs, The Smiths, Spandau Ballet? What happened to the 80s? The truth may be that people aged between 15 - 25 in the seventies are now in positions of power in radio and television. It may be, but I’m not sure.
- Bob Dylan’s “Mr. Tambourine Man”
- The Beatles’ “Tomorrow Never Knows”
- The Who’s “Won’t Get Fooled Again”
It would be possible to make a very long list, you realize that.
Highway to Hell
or
Ted Nugent - Strangle Hold
Wait make that
Egar Winter Group - Frankenstein
:Holds lighter aloft:
FREEBIRD!!
FREEBIRD!!
:Lowers lighter as it starts to burn my hand:
Born On The Bayou – Creedence Clearwater Revival
Dream On – Aerosmith
Turn The Page-- Bob Seger
Piece of My Heart-- Janis Joplin
Misty Mountain Hop-- Led Zeppelin
Come together,
Right now,
Over me.
Wild Horses or Sympathy for the Devil.
Classic Rock: Can’t Get Enough Of Your Love - Bad Company (one of many favs, many of which have already been mentioned)
Classic Rock And Roll: Rock And Roll Music - Chuck Berry (also one of many favs)
Twist and Shout
You can’t leave out the best kiss off song of all time - Go Your own way by Fleetwood Mac!!!
I am shocked that no one has got the right answer to this question yet ;).
Cream’s cover of the classic Robert Johnson blues song Crossroads, recorded live, is still one song that after all these years I can listen to again and again. The song itself reminds me of the roots of all rock and roll. That, coupled with the absolutely hot, rippin’ licks those boys laid down puts it at the center of my R&R pantheon. When I listen to this beauty I am continually amazed that this was just a trio, and that Jack Bruce didn’t break any of the strings on his bass on the second trip through their solos…