I've had my Mini for 15 months, and have put 17,000 fun-packed miles on it. I have the base model with manual transmission, sport seats, and a sunroof. Although I have read reviews that say otherwise, I think the base model packs plenty of power (as long as the A/C is off). I have not tired of this car - each time I get in it, I am reminded of how much fun driving should be. It is responsive on turns, and stable as can be at high speeds on the freeway.
The responsiveness, visibility, sport seats side bolstering, and large sunroof.