I sampled the 911 Carrera and the Targa 4S within about a week of each other, after not having piloted a 911 in a few years.
The Targa was a car I really want to get my hands on and it was magnificent. But it's also a 911 that, besides having a targa-style roof, sports a 420-horsepower motor, a notable bump up from the base Carrera. The Targa 4S also had all-wheel-drive, versus the Carrera's old-school rear-wheel drive (yes, there is a lot of variation among 911s, and you can check them all out here.)
Frankly, I'll always take less horsepower and RWD on my sports cars, any day of the week. The Carrera's 370 is already plenty of beef — the additional 50 horses for the 4S were for me needless. Sure, you can feel the oomph when accelerating and passing, but you're just not going to get into all 420 horses, not in the same way as the Carrera's 370.
And although the 4S gives the impression that it's fail-safe, it's almost too mannered. The Carrera isn't wild, but the balance of the driving dynamics is what I favor in the 911: rear-engine ripping out that pure Porsche growl, power going down to the rear wheels, idealized steering pretty much telling you where to put the nose. If you want, you can force matters and get the back end to slip. Under the right conditions, the 911 is the most festively oversteering machine imaginable.
That's risky and even with all sort of modern traction management systems, you can still feel the 911's rear wheels wants to do their thing. But that's really a safety feature. Overdriving this car in civilization is a bad idea. It forces you to assess your skills honestly and behave accordingly, lest you put $100,000 in peril.
In any event, as I wrote in my review of the Targa 4s, for me the 911 has always been the most self-contained of fast and fun cars. The Ferrari 458, for example, contains a screaming V8 located amidships. Press toward the red line and your eardrums could bleed. A Lamborghini with a V10 creates a wild symphony of exotic burps from its yowling V10. A Corvette Z06 has its 650-horsepower V8 parked up front, and the roar coming out of the exhaust pipes in the back is borderline unholy.
Against this rude cluster of supercars, the 911's behavior, sonic or otherwise, is subdued. Powerfully subdued, but subdued nonetheless. I'm not saying it's quiet. But it offers just a subtle indication of power by comparison.
What really makes the 911 so great, and invariably leads me to conclude that it's the finest car on earth and always will be, all happens when you slip behind the wheel. Obviously, this could be me, but the car just feels right.
The 911 isn't the perfect sports car — it is, in fact, a bundle of adaptations and workarounds, gradually executed over many decades. What it is, is the sports car perfected.
If you want to have fun behind the wheel, get one. You won't look back.