Well first has to be the Spitfire - probably second only to Concorde as the most beautiful aeroplane ever, standing still or in flight. The Hurricane was a bus in comparison - a Fury with the top wing removed and the thick wooden lower wing still on. It was the major scorer in the Battle of Britain, but only because at that time the RAF didn't have enough Spitfires.
The DC3 of course is there as well. As is the Tiger Moth (though as I know from experience it's not the best handling aeroplane - the Chipmunk takes that accolade for me).
Of the Cubs, it has to be the J3 (or, in my experience, L4 military version). Simple, but so 'right'.
The Lancaster and Mosquito would be my piston bomber choices, and the fabulous Vulcan my jet bomber choice.
Jet fighters - the Hunter for its grace and the Lightning for its brutality.
And the Harrier of course. So much more elegantly KISS than that modern US VSTOL thing.
The 747 because it changed the airline industry.
Concorde was just the pinnacle. Not really a classic as it was unique in what it did, just the best ever thing that flew. It suffered political pressures and assassination, the US and USSR tried to do it and failed, and it gave us almost 30 years of regular London - NY in just over 3 hours.
4.5 hours at M2 is something unheard of before or since, even ignoring it did it with 100 champagne-slurping shirt-sleeve luxuxry customers on board. And to this day it's the only aeroplane to fly the Atlantic supersonic (double supersonic, actually), without in-flight refuelling.
So for me Concorde is the pinnacle of flight, the classics follow in its wake.
