It is very hard for me to not repeatedly listen to the best rock and roll song ever recorded: Dirt by The Stooges:
http://www.youtube.com/watch?v=zxYXV2RrwIsI say best rock song somewhat flippantly (it is certainly tied with like 100-1000 others for that top spot though), but seriously, a perfect groove that doesn't really change, the perfect amount of guitar and guitar effects, and lyrics that anyone with any type of experiences and ability to think about their life can associate with, sung by someone who sounds infinitely cooler/harder/more experienced than you- does it get better in rock than that? Oh- and the lyrics are depressing but also uplifting.
here are some other, different sounding, perfect songs:
Olivia Tremor Control- Jumping Fences:
http://www.youtube.com/watch?v=jUjd6DHAutUBob Dylan- It's Alright Ma (I'm Only Bleeding):
http://www.youtube.com/watch?v=biqqz0aoOtYQueens of the Stone Age- The Lost Art of Keeping a Secret:
http://www.youtube.com/watch?v=0l0nzPpvbFsCloud Nothings- Hey Cool Kid:
http://www.youtube.com/watch?v=F1A3LKdgljMJEFF the Brotherhood- Bone Jam:
http://www.youtube.com/watch?v=I9wmFRSVAKwQuix*O*Tic- Anonymous Face:
http://www.youtube.com/watch?v=970CL4BIMU4and like a few hundred more (I didn't even include Cinnamon Girl! Or the Pixies, or the Damned ororororororor). Also, personal story time: One time I was listening to the last song with my roommate. We had just gotten high on herb and were going to go to a party- he was all, hey, lets go after this song. His ipod or whatever was accidentally on repeat one, and the album cut of that song doesn't have the space at the end- we probably listened to that song for 20 minutes before we realized and left.