I like the 368 Street Racer. It looks like a "no frills, just thrills"-machine, with agressive curves and narrow width.
I also like the Berlina Sportiva, altough it would probably do better as a replacement Maserati Quattroporte (and that ain't bad).
On the list is also the Chiaroscuro. Other than the fact that I love dual-color and multi-tone paintwork, the lines of this car are right up my alley. Looks like a real GT too.
The rear wheel-arches, or should I say hips, of the Duo Masse also catched my attention, looks like a machine between the current F430 and Enzo.
Oh, and the F-Zero too. Except it doesn't say "Ferrari" to me. Looks way too heavy.