Fantasy sports: ultra-performance and luxury sports cars: for the price of a condo, you can buy a dream machine. But is it worth the price in reality?(SPECIAL AUTO SECTION)(Buyers guide)

Owning a high-end sports car is an aspiration for many people. They dream about buying one for years, and when they reach the point when they can afford it, they splurge. But the choice is too often based on dreams rather than real-world performance. So, here's our wake-up call.

Is the Mercedes-Benz SL $52,000 more car than the SLK? Would you rather have a Porsche Boxster and $40,000 in the bank than a Porsche 911 Carrera S? At prices ranging from $67,084 to $105,855, do these cars deliver enough performance and excitement to justify the price?

Our test cars fall into two groups, ultra-performance cars and luxury coupes. The first group consists of the 911, Chevrolet Corvette Z06, and Dodge Viper SRT. Each car is thrilling to drive with extremely high levels of acceleration, cornering grip, and braking. In many categories they set new performance records in our testing. While they're built for speed, the 911 and Z06 are civilized enough for everyday driving. Driving the Viper, however, can be punishing.

The 911 wowed us enough with its acceleration, handling, and braking for us to rate it our top sports car. It is also easy to drive, but its much less expensive Boxster sibling performed almost as well.

In S trim, the 911 has a bigger engine than the base Carrera, as well as upgraded suspension, wheels, and tires. Starting out at $81,400, our 911 has sport seats and a built-in stopwatch on top of the dashboard, which costs a ridiculous $920. In total, we paid $87,520. We don't have reliability data for this Porsche.

The Corvette Z06 was very impressive with super acceleration coming from its 7.0-liter engine and excellent handling. It ranks just below the 911 in our Ratings. Several functional air scoops and flared wheel arches help distinguish it from the regular Vette. The Z06 comes only with a six-speed manual transmission and starts at $69,175. List price on ours with satellite radio, a navigation system, and a power telescoping steering wheel was $76,730, a relative bargain for this performance level. Corvette reliability has been much worse than average so we do not recommend it.

The Viper SRT is the fastest car we've ever tested with staggering power and grip, but its lack of creature comforts cost it dearly in our tests. It comes in roadster or coupe versions and is powered by a monstrous 8.3-liter V10 engine. Our coupe had a base price of $83,415. Options such as leather trim, dual white stripes, and polished wheels brought the sticker up to $91,990, including a $3,000 gas-guzzler tax. We don't have reliability data on the Viper.