Well, what is it? I know that this forum is skewed towards the Japanese stuff but there has to be a soft spot for something from Europe.
Here are a few of my faves, all from the 90s:
E73 Brabus
R129 Renntech 7.4
Audi RS2 Avant
Koenig Benzes
Fiat Turbo Coupe 20V
Alfa Spyder/GTV 3.0L