2007 Jeep Grand Cherokee SRT-8 4dr SUV 4WD (6.1L 8cyl 5A)
In spite of a few reliability issues (e.g., occasional erratic A/C and occasional erratic power), this car is built like a tank and accelerates 0 to 60 in about 4.8 s! For a 5,000 lb SUV for less than $50k, this is fantastic. It also handles well and is less prone to roll over than many other SUVs. And, it looks good too. I would not hesitate buying another.
Rear seating area should be enlarged by perhaps 6 inches and the rear seats need to be higher (for leg comfort). Of course, you would have to add more power to compensate for the extra car length. Finally, use graphite, titanium, and magnesium to lighten the car and get better gas mileage.