It always makes me laugh when people argue over what's best, in most cases peoples likes in music are all to do with what era they were growing up in, yes I appreciate for example some of todays younger generation may like the Beatles or the Stones (if like my kids they heard it all the time...
Not to sure about "Best" but my favourite track is "Come up and see me" Steve Harley & Cockney Rebel.
I think I would have to give my vote to "Won't get fooled again" by The Who as my Best track, in my opinion it's awesome in every way.