No contest. Supra all the way. The RX-8 handles well, but it's slow off the line and gets poor mileage. If you can find a Supra that hasn't been tainted by a tuner or drifter, you'll have yourself a future classic.
I would pick Supra too but if I have a free hand to choose on other cars then I would pick either a 300ZX TT or a 350Z. noticed that the OP got banned for whatever reason so he might not reply here.