2008 Chevrolet HHR SS 4dr Wagon (2.0L 4cyl Turbo 5M)
All I can say is "Man is this car fun to drive!" And I'm just finishing up about 10 years of driving a BMW 5 series and X-5. The torque and acceleration are just awesome in this car, and I don't even have the Stage 1 Kit installed yet. Even though I have an AT rather than Manual, it is still fast and still fun. I've only had it for a couple of weeks, so I'm sure the glamor will wear off, but for right now, this car is a blast to drive. I can't speak for the other versions, but the SS is the way to go if you are into performance as well as looks.
The turbo is great, and I love the little boost meter on the left side. The gas mileage is much better than my x-5. And although the back area is pretty small, I can still fit my golf clubs back there, which is all that matters.
Having some tint on the driver and passenger windows. Deeper cup holders. Homelink garage door opener in the visor. The Stage 1 kit as an option. Painted break calipers. Headrest DVD system.