2008 Audi RS 4 quattro 4dr Sedan AWD (4.2L 8cyl 6M)
I purchased the 2008 RS4 in July 07 and took delivery toward the end of October 07. I have not yet had a good chance to put it to any serious tests. However, from what I can tell so far, it is an extraordinary car and has exceeded my expectations on most accounts. You'll be amazed at how nice the car feels driving on mildly winding roads at 30-50 mph, and you'll be equally as impressed with it's ability to easily handle the same at 75mph. Acceleration is actually scary during the first week. All the other aspects you expect (the exhaust sound, the "sticky" 4wd, the short throw, the seats, etc.) are exactly as you'll hope: perfect. Chose this over 335xi and M3, no regrets at all.
I love the understated nature of the car (though it receives many quick "double takes"). I wanted an extraordinarily fun car to drive that is mature and mildly sporty (looking). In terms driving, I can't say enough about the low speed comfort. High speed goes without saying.
This car needs an option to have a digital speedometer right in the middle of the dash. The dial off to the right is not effective when negotiating gears and roads in a car just itching to break speed limits. Perhaps it's there and I haven't found it yet.