I mostly meant that Porsche in general makes the most livable high-performance sports cars (like Ferraris, Astons, etc). I have no anti-ricer bias at all... my favorite car I've owned is still my '97 Prelude SH.
The Mazdaspeed 3 is a great little screamer, but it's not in the high-performance category. The GTR/Skyline certainly is, though!
NSX and 300 ZX are no longer available. The 370Z will run with a Cayman, though.
S2000 is not that livable as a daily driver in my book.
The Car & Driver editors would take an M3 over a 911, so that's certainly in the running, too.
The STi might beat a 911 C4 on a snowy road, but not on a track.
Anyway, those are all fine choices in their categories.