I like all Ferraris - they are my favourite sports car manufacturer. I like the F430 a lot, but the F40 definately still reigns as the hardest looking one IMO!
If and when I could afford one (and it would be the cheaper end of the scale at that!), I would choose the F355 which is quite handy as it's my favourite one (well pending a drive of one next month at Thruxton

!)
Only my opinions of course