Ooh, I dunno...Stairway to Heaven is about as cliche as ya can get.
If were talking Rock n Roll...
Free- "All Right Now"
Stones- "Satisfaction" "Brown Sugar" "Honky Tonk Woman" "Sympathy for the Devil" "Jumpin Jack Flash"
Chuck Berry- "Johnny B Goode"
Steppenwolf- "Born To Be Wild"
Beatles- "Come Together" "Twist and Shout"
Bruce- "Born To Run"
Cream- "Sunshine of Your Love"
Clapton- "Layla"
Elvis- "Jailhouse Rock"
Roy Orbison- Oh, Pretty Woman
Creedence- "Born on a Bayou"
Little Richard- "Long Tall Sally" "Good Golly Miss Molly"
Jerry Lee Lewis- "Great Balls of Fire" "Whole Lotta Shakin Goin On"
Jimi- "Purple Haze"
And for me, Led Z's "Whole Lotta Love" had a much greater impact on rock music than the aforementioned "Stairway to Heaven" It came out earlier...it was one of the first HEAVY acid rock songs.
Now, I realize these are all rather old...but I think they are songs that were quite influential...or just damn good.
I love the Eagles and some of the other songs mentioned here...but they just don't fit into "rock"...well, maybe Life in the Fast Lane...and Hotel California...two GREAT songs...do.
I'm sure I missed a bunch.