Uh....cause they are Fords? After the death of the GT, Ford doesn't really make a "must have car". The Shelby GT500 is appealing to s certian subset, specifically Mustang guys and power junkies.
On that list, 4 are German (I'm counting the Mini Cooper as German, the name and heritage may be British, but the new car is all German), including the top three. The rest are all Japanese. Prices range from the sub $20K (Mini, tC) to near $100K+ (SL [600, 65], 7), which is interesting. Also nice to see a range of cars in different stages of their model's life. The Cayman is new, the SL styling is old, as is the Cooper and tC, some other are newly refreshed: 7, M, IS, etc.
One Prosche, one Benz, two BMWs, three Toyotas, and three Nissans.
Regardless, all of these cars share similar qualities: distinctive styling. Most also have the "rare factor", where in most parts of the country, you'll not see those cars on a daily basis. That makes them appealing. Usually, most people don't desire a car they see droves of everyday. Which is probably why cars like the Mustang and 300 aren't up there; you just see too many of them to still have that certian something about them.
Nelson-
Nice additions, but again, those two cars really appeal to a small group of people. Most people don't know what a Lotus is, much less an Elise.
For what it's worth, while I find most of those cars appealing, they wouldn't be on my Top 10 list. I imagine the list is limited to new cars, which would mean almost all of my Top 10's would be eliminated. I do like the new IS's, but like the old Infinity M's better.