In terms of distinctiveness, you can't beat the Dodge Tomahawk, with a Viper V10 engine. Absolutely crazy!

500 bhp (372 kW) @ 5600 rpm (60.4 bhp/liter); 525 lb.-ft. (712 Nm) @ 4200 rpm
10-cylinder 90-degree V-type, liquid-cooled, 505 cubic inches (8277 cc)
356-T6 aluminum alloy block with cast-iron liners, aluminum alloy cylinder heads
Bore x Stroke: 4.03 inches x 3.96 inches (102.4 x 100.6)
0-60 mph: 2.5 seconds (est.)
(Some estimate 1.9)
Top Speed: 300+ mph (est.)

and for one of the most beautiful, I nominate the Alfa Romeo 8c Competizione. The first time I saw this in the metal my jaw hit the ground......The car is stunning.