That is a touch question mate,there are so many smashing tracks out there can I have 3 or 5 or something. You might not even like my techno/breaks/old skool flava, here’s one of my best anyway,

http://www.youtube.com/watch?v=P385-oDwQ6g

or this is another great that I have come to love so much

http://www.youtube.com/watch?v=dlvgtEiOc74

Ohh yeah, that’s a blinder, A good buddy who makes mixes from this website got me into it. I had a mad acid trip to that tune, I was imagining loads of industrial valves and pistons all pumping and I was travelling along underneath them. LOL techno does kinda sound like a moving engine sometimes. lol

I have waaaaay to many to be fair, i can’t list just one and it changes all the time anyway.
Fuck, theres a trip down memory lane, i used to love the autobots

http://www.youtube.com/watch?v=hZF3xzKAKzQ

Always Look On The Bright Side of Life – Life Of Brian (Monty Python) Lyrics – YouTube

There is no one greatest song, different music for different moods, surroundings & company

@barrettone 514897 wrote:

Hard to say. “Echoes” and “Time” by Pink Floyd are right up there, as is “Weird Fishes” by Radiohead. “Only Shallow” and “To Here Knows When” by My Bloody Valentine, “Schizophrenia” by Sonic Youth, and the “Turangalila Symphony” by Olivier Messiaen are all songs I never get tired of.

Ahh man i well agree with those first 3. Weird Fishes is such an awesome chill tune.
Actually i may have to go with echoes – that is a 20 minute masterpiece that never gets boring.

Theres mamy but if off the top of my head,negative creep by nirvana