Agreed with some of what other people mentioned already.. comparing cars is pretty much up to personal preference. But..
Before I got a 34 GTT I have test driven 33 gtst (modified and stock), S15 J-Spec, S14 Stock Aust delievered, gtir stock (?) (just for the hell of it) . S13/silvia and silvia I didnt bother cause I wanted a newish car.
I must say 34GTT is still the car to get, depending on what you wanted a car for. The GTT has better interior (standard), turns more head and more room! than an S15 or S14 or even 33.
I would agree to say that 34 GTRs.. ooo... gimme one..