I totally agree with all the Steely Dan songs listed here.
But, just for comparison sake, I'd like to nominate the Beatles 'A Day in the Life' from Sgt. Peppers.
In a time of analogue everything, and 2 or 4 track studio recordings, this track set the whole world agog!
The haunting emptiness of Lennon's vocal - The dropped in orchestial orgasm -the incredible 4 piano chord to close and the 38 second tail.
It has never ceased to amaze me what George Martin and his staff accomplished with the primitive, by todays standards, equipment.