My list...
1. Ford GT (timeless design)
2. Lamborghini Gallardo spyder (sexy)
3. Viper GTS Gen II (classic proportions)
4. Ferarri F430
Honestly, thats it for me. The Enzo is UGLY...the F1 is a technical tour de force but aestheticlly leaves me cold. All 911s remind me of VW beetles or overturned bathtubs.
Virtually every other "supercar" in my opinion, is either over the top (e.g., Countach, Veyron), derivative (NSX), plain (Corvettes except some of the 60's models), ugly (Caterham) or just plain wierd (Zonda).
Eric