I think the big question here is "What do you really want in a car?" Having some info on what you want to use it for would help a lot. As for me, I'm a fan of used cars because of the massive savings. I've got a '68 Mercedes 250SE, '84 Alfa Romeo GTV6, and a '79 Ferrari 308. I also used to own a '82 Mercedes 300SD. All these cars are VERY different from one another and each is more suited to a particular task than the others. So the best car for you completely depends on what you will be doing with it.
If you plan on getting a Mercedes, stay away from anything made after '98. Reliability on these things used to be bulletproof, after the '98 model year though things took a turn for the worst. On my '68 I haven't had to replace anything at all after almost 6 years of ownership. On the '82 I didn't need to replace anything while I owned it (about 2.5 years) Bulletproof.
Currently the Japanese are the kings of reliability. If repairs frighten you and you want something newish, go Japanese. For fun 2 seater coupes you've got the Honda S2000. For getting around town it's hard to beat Toyota's lineup, specifically the Corolla and Camry. If you want to spend a little more you can get a Lexus. I'd go with a toyota over a Lexus though. Same company but a whole lot cheaper, kind of like the Acura/Honda relationship. The Japanese have also managed to smash the competition in the "ugliest cars on the road" race with the Scion lineup and of course the Honda Element.
I'm a huge fan of the italian cars. They've got abysmal reliability and the parts often cost more to buy than it would cost to actually have a machine shop fabricate the part for you, but for pure fun and style Italy is where it's at. Unfortunately in the U.S. our choices are limited to cars from the mid 80's and older unless you want to spend somewhere over 50 Gs....Still the handling of these cars, even the older ones is the best on the planet. Gas mileage should not be a concern when buying one of these cars. On a good day I get 20MPG on the Alfa and 9 MPG on the Ferrari.
Speaking of gas mileage not being a concern, Ford and GM. Um, stay away. The new Mustang is an attractive car that is rather suicidal around the curves due to its live rear axle. 99 times out of 100 the american cars will take a huge dump in value in an alarmingly short time.
By the cars that you mentioned in your post above, can I assume that we're working in the 15k-20k range? If so I'll give you a couple recommendations.
If you want a sporty and fun two seater, go with the Honda S2000 (used, under 20K)Or the Mazda Miata which is a bit cheaper. Be forewarned that the Miata has a reputation as a "hairdresser's car" even if it is a fantastic car. You could also go for an older italian...just be sure to keep a few bucks for a taxi when it breaks down
If you want luxury, get a Mercedes E class. The E320 and E400 are great cars and pretty much bulletproof from what I've seen. People often conside these the last of the "real" Mercs.
If you want an SUV, get in the right hand lane. You're in my way and I can't see around you. : )
For economy and sensibility, go Toyota. The Camry is a very good car. Cheap repairs, good fuel economy, easy to live with. New ones are in your price range. Used ones are the exact same car and half the price.
If you don't care about reliability, fuel economy, ease of use, or safety, Get a Ferrari Mondial. They're old but starting to creep down into your price range. It's also got 4 seats so you have room for a bike to get you home when it breaks down and leaves you with a $15,000 repair bill. Why would anyone want one? Because there's nothing better in life than saying "My Ferrari" when you see it in the morning.
Whew, long post.