<--Total and unapologetic wingnut.

Super Connie, 747 and Concord....the clear choices for civilian birds based on non-wingnuts being able to pick them out of a crowd. Each pushed aviation into unchartered territory and then stuck around long enough to become an icon.
The 727 deserves a lot of credit too.

SR71, Spitfire and (controversially) F16 for many of the same reasons. The Viper gets very little credit for all the new ground it broke, while doing so on the cheap. We could put the MiG 15, 17 and 21 in the same bucket.

Not-as-easily-recognized by non-wingnuts, but equally important:
Harrier, Tu95 "Bear", B90/200/350 King Air, Lear 23, X1.