Can't narrow it down for me so I'll just list a few an list them from unreasonable to realistic.
Money no object only one answer for me, the road legal version of the Panoz GTR-1 race car.
more photos here http://www.forocoches.com/foro/showthread.php?t=79872
Vector W8, mock it all you want but you can't deny it looks bad ass.
De Tomaso Mangusta, everyone loves the Pantera but I just think these are extremely pretty cars.
Renault R5 Turbo II, love these little things, can't get much cooler then a mid engine hot hatch.
Delorean DMC-12, I've been in love with these ever since I was a little kid, got to sit in one for the first time at a car dealership a few months ago while helping my bro look for a new car. I can guarantee that if I had the money I'd have bought it then and there, wasn't in the best shape but who cares its a delorean!
Pontiac Fiero, yah I know not the greatest car in the world but I've test driven a few and they all did the exact same thing a great majority of the cars I've driven don't do, it put a huge grin on my face and thats all that matter. I would love to have one of these.
There are many more I could list but I wanted to keep this short.
edit: darn didn't realize there was any sort of limit to the number of pics that could show up oh well at least the links work.