I haven't driven any of them, but I say go American. That being said, my experience with the TT and S2000 are as follows:
Recently toyed with a TT in my Porsche 928S4 5spd, he floored it, I floored it and about ran right through him he was so slow, let off the gas, let him get a car length lead, floored it and I was immediately all over him again. I did this several times, like a cat playing with a mouse, batting it around letting the mouse think it could get away then smacking it again. (Too much traffic to actually blow by the TT and it was actually more fun to toy with it.)
With my previous car a 93 RX7 TT 5spd, I beat a S2000 easily as we both accellerated from a stop light up a highway ON ramp that was 2 lanes.
I don't care for the looks of the Porsche Boxter (not on your list) I did until I saw it has 1 exhaust pipe coming directly out of the rear center, kind of resembeled something if you know what I mean.
I don't care for the TT, if you want one why not get the VW convertible?
The Honda and BMW are both nice looking vehicles, I think the Honda is lacking in torque which is what kept me from even looking at one. I had to deal with NO Torque with the RX7. The BMW would be my choice without actually having driven any of them.