what is the best rock n roll song of all time?

My wife was kind enough to record a Crosby Stills and Nash concert from 2012 that was on the AXS channel on uverse earlier this week. Watching it reminded me to add Teach Your Children and Suite Judy Blue Eyes to the list of great songs worthy of consideration. They are probably a bit too easy going for purposes of this discussion but deserve an "honorable mention". As an aside, during Suite Judy Blue Eyes, Stephen Stills played an acoustic solo that included a few riffs from Within You Without You (very psychedelic Beatles song) which was a very cool moment. It seemingly caught Crosby and Nash by surprise based on their expressions and Nash even leaned over towards the microphone and mumbled something about "George" with a bemused look on his face. Definitely worth a quick view if you get a chance to watch.