In order:
Lexus IS350: Speed, looks, reliability, luxury, handling, the works. The IS250AWD is much slower than the G35x so it might be a push then. I have to say though, the interior of the G35 did not compare at all well with the Lexus.
Infiniti G35x: Best value for the money probably and AWD is a plus I guess. Unimpressive low rent interior, slightly better interior than the BMW but that's not saying much. Not a big fan of how it looks.
BMW 328i: Test drove one, didn't like it, didn't feel as if it was anything special. Panel gaps were bigger, materials were subpar for the class(example: exhaust tip is galvinized steel, not chromed, lack of upscale interior trim, etc), handles and drives pretty well
Acura TL: Looks nice, okay power(more than the BMW on the highway), decent interior but FWD luxury sedan?