I'd say my first choice would, of course, be my LS RX-7.
But other ideas I've wanted to do have been:
Either one of these two with a nice n/a LS7 with a quiet exhaust and a cutout
http://www.newcelica.org/photopost/data/500/medium/bmw-e38.jpg
http://www.newcelica.org/photopost/data/500/MERCEDESBENZSL-R107--1728_6.jpg
Another cool fantasy toy car would be one of these, even completely stock I'd be happy with it.
http://www.newcelica.org/photopost/data/500/Renault-Clio_V6_Renault_Sport_2003_photo_07.jpg