If you want a out of the box sport car, then get a s2000. Not the fastest of the bunch, but it's reliable with no bullshit problems.
Somebody mentioned a 300zx. My friend has a 91, and all I can say DAMN! Fast car, great handling, looks great. But, and this is a rather big but. If you work on your own car, then you will grow to hate it. It has one of the tightest engine bays I have ever seen. Even after ripping out all the emissions crap, and the usual mods, there is still no room to turn a wrench.
Now the 240, another great car, but not stock. Let's be honest, the American spec 240's are shit untill you drop some money on it. Car basically needs a new drivetrain to be a competitor.
The holy grail of Japanese imports. The skyline R32, 33, 34 I don't care, all are hot. If you can get it registered, and you're willing to deal with parts. Then this is the obvious choice.
Just my input