I have owned my '94 Jeep Grand Cherokee for over a year now. It is my first vehicle and my mom also owns one (1998 though). It is very reliable and the only problems have been mostly from abuse of past owner. The CV shaft on the driver side was badly torn but other than that, no major problems. It handles well on-road, as well as off-road.
I would say my favorite feature is the strong 5.2L engine; although poor gas mileage, I wouldn't change it for anything.
I can't think of any major improvement at the moment.