I DO have thoughts on this subject I mean, I'm a guy who just had to choose between the E39 M5, a turbo Miata and a CRX Si to run around town. All of them get use, and I like them all for daily drivers.
Ransom thinks along the same way I do. You want something alive and eager, ready to play. That could mean massive amounts of torque waiting for a little tickle of your foot, it could mean a good chassis with relatively low grip.
Our M5 is in the former category, you're always aware of the massive reserves of speed available but it doesn't beat you up about it. A V8 NA or NB Miata, well, you're a little more conscious of what's underhood and it's a bit more in-your-face about it all. The V8 ND doesn't ask for a compromise. It's more like the M5. The performance is there, but under a veneer of civility.
The CRX is the latter. It's a fast slow car. It's fun to drive because it's involving, but not so much that it's exhausting. The classic Mini is more of the exhausting type, it's a puppy of a car that is always asking more of you.
The turbo Miata is the good chassis with some punch. You don't know the turbo's there until you ask for it, but it's still not the same as a big displacement hit. It's a good all-rounder, a quick car with an engaging chassis.
One thing all of these cars share is good suspension - and none of mine are stock in this regard. You don't want bad suspension in a daily driver, it'll beat you up. No matter what you choose, pick the car with composure over all surfaces instead the one that can lap 2s faster at the 'Ring. This might be one step down from the ultimate level, as Streetwiseguy has said. Although the advent of magneohetrological (sp?) shocks may be changing that.
I never through the FD (most recent) RX7 was a great street car. Fast (at the time), no question. But it wasn't accessible speed. You always felt you had to hold back. The S2000 gave me the same impression, you just couldn't play with it on the street. I've got very little Porsche and no Corvette experience, but the original Boxster on the street seemed to have a pretty good mix of attributes. So it's not so much about the ultimate speed of the thing, but about what it requires to have that speed. A high revving naturally aspirated superstar motor is wasted on the street, a big hearted bruiser is more fun.