It's called the law of diminishing returns: the idea that, after you pass a certain threshold, your investment no longer corresponds to your reward. It also applies to sports cars. There's a kink in the price/performance graph where you begin spending a lot more money for not much more performance. There's an easily definable point after which come diminishing returns, and that point is the Chevy Corvette.
Certainly, there are faster new cars than the Corvette. But all of them, without exception, cost a lot more money. The base Corvette handily outguns the Porsche 911; the Z06 can hang with the Ferrari F430s of the world. And for 2008, the Corvette got a comprehensive overhaul, with up to 436 hp available from the 6.2-liter LS3 V-8. The revised car does the 0-to-60-mph sprint in 4.3 seconds - with an automatic transmission.
At this point, Chevy could probably say, "Here's a car that goes 190 miles per hour and costs forty-six grand. You don't like the steering? Bite me." Instead, it rolled out a car that does 190 mph while also addressing the subjective aspects of the driving experience. The steering got a new machining process for its internal components, in the name of improved feel. The shifter was revised, in search of more direct throws. The interior, long a Corvette weak point, got a new option that can be best surmised as "cover everything in leather." The 2008 Corvette is like a prodigal athlete who's not content to merely destroy the competition - now he wants to do it with style.
When you think about it, elite performance cars tend to remain essentially unchanged throughout their lives, maybe because they're already as high-strung as their manufacturers can make them without starting over from scratch. A BMW M-car, for instance, gets only minor changes over the course of its life. But Chevy tore down the Vette and found meaningful improvements halfway through the C6 production run, when it could've easily said, "You know what? We'll fix that stuff in the C7."
It's not like there's a car waiting in the wings to usurp the Corvette's title of Supreme Sports Car Bang for the Buck, but Chevy acts as if there is. And that's why the Corvette is, once again, an unequivocal All-Star.