The LFA has a nice body design, the Lambo Veneno is cool but a little over the top in terms of conceptual/ultramodern design, and McLaren is awesome, but nothing beats Ferrari. Sesto Elemento has a pretty cool body design also.
The next car I'm planning on buying new is a Nissan GTR, maybe in a year or two, a car line I've wanted since the Skyline series. The new body style as of '11-'12 is mean and the stats are mighty impressive. As far as Lamborghini goes, I'd love to own one of the first model Countachs or late 90's Diablo, the Reventon is a hell of a car too.
My current dream car would probably be LaFerrari, just a vicious design with racing in mind
Though I wouldn't say no to a 458 Italia, was at a 458 race special a couple weeks ago and the cars were gorgeous.
For now, Forza for xbox is my way of owning impossible supercars lol.