I recently bought an '06 CL55 AMG with low miles. It is the best looking big coupe MB has ever built, far better looking than the current body style, in my opinion. It is an absolute blast to drive... it has tremendous power and torque, faster than a speeding bullet and able to leap tall buildings in single bounds. It makes you feel like a superman driving it. The AMG seats are the best I've ever sat in, with more adjustments available than a chiropractor. The only downside to the vehicle is the gas mileage - 17 in the city, 19- 20 highway. When you pay $75 to fill a 21.5 gallon tank, it kind of hurts. Until you press the engine start button. That that big grin takes over.
Start button, seat controls, very slick in-dash NAV/CD system.
I fell in love with this car, the handling, and the wonderfully powerful and smooth engine. I continue to enjoy the well-crafted and reliable engine (each engine is hand crafted by one person, and signed by him/her) and the excellent ride. And the car looks sharp, inside and out. But I will bot purchase another Mercedes. The "cons" are just far too many for a car that is $140K+. I average 13mpg (city driving), premium gas only. I have had to buy new tires on three occasions now (with less than 15,000 miles) They are fat tires and pick up all nails and cannot be patched. And tires are $500+ each. And reliability of non-engine components (electrical system especially) is awful.
Engine -- the sound (purrrrr) and performance. Speed. Design and handling of the vehicle.
Mileage is horrible (10 - 13mpg city, at best). Poor tires. They have to be replaced often (more so than any other sports car I have ever owned). Very poor reliability for electrical system and other componets.