Too many dream cars to name them all, yet very few that are actually available, to me or to anyone else.
Dodge Charger III concept car:
http://www.carstyling.ru/cars.1968_Dodge_Charger III.html
This would be fun to recreate as a kit car - make it fit the plentiful Corvette chassis out there, but power it with the Hemi crate motors from Mopar; the concept had an original 426 Hemi in it, and braking flaps. You may have had the Matchbox toy of it (and the Twin Mill, one of the most famous Hot Wheels, was clearly designed with the Charger III as its basis).
Batmobile (the 1966 TV version): this one is a little more possible - there are companies and individuals that offer body kits of this. One of the buyers is building one on a Viper chassis - it's going to be awesome when it's finished. Mine would do without the labels and silly tings in the interior, and have serious seats and instrumentation.
1934 Ford Tudor street rod - built as a 2-seater with extended doors and the rear door from the sedan delivery; a "GT" version of the venerable hot rod, with the latest Ford Racing 5.0L engine - supercharged, of course.
1963 Ferrari 250 GT Berlinetta Lusso - it was good enough for Steve McQueen!
1968 Jaguar E-Type 2+2 - cargasm.