For me, the all-time Big Five for me would be:
DC-3
Constellation
707
747
Concorde
Each one of them did something groundbreaking in civil aviation. I could be talked out of the 707 in exchange for a Comet, I suppose.
Some of you guys are throwing in military aircraft... If we're going there, then I would put a backseat ride in an SR-71 at #1.

But I don't suppose any civilian has ever gotten that privilege...