I suprised nobody has posted this yet:

The shark-nosed Dino
Also here are some of the more recent cars that I think are quite underrated in terms of beauty.

EJ12.

C24 - quite stremlined design with the maddest undercut sidepods of the 00's.
Didn't perform very well though...

MP4-19B. The Monza one-off version of the car that made a TV presenter run a lap of Silverstone naked.

The early version of the STR02.