Don't get me wrong I don't hate supercars....its just that I'll never own one, even if I could afford one, I probably wouldn't have one. Maybe a Porsche Twin Turbo Carrera or something. A Z06 would be cool too. Though not a supercar.
Anyway...arguably one of the baddest supercars is the Vector Aeromotive of California's Avtech WX-3. Amercian made with a 250mph top speed!!!!
I believe they were bought out by a European firm and have pretty much disappeared from the earth.
here are some specs:

Vector Avtech WX-3

Engine
7.0L ŠV-8t

Power (bhp)
1000@5800rpm

Torque (lb.-ft.)
700@4100rpm

Performance (0-60mph)
3.3sec

Top Speed (mph)
249