Just a few of my favorites:

Comfortably Numb- Pink Floyd

Bohemian Rhapsody- Queen

Stairway to Heaven- Led Zeppelin (Stereotypical, YES, but good none the less)

Time- Pink Floyd

All Along the watchtower- Hendrix version

While my guitar gently weeps- George Harrison

I won't back down and Learning to fly- Tom Petty

And some of the best songwriting i've heard is by the "Traveling Wilburys". A great band with Bob dylan, jeff lyne, tom petty, roy orbison, george harrison, and some other people i cant rember right now.