Had to have the A/C evaporator replaced. The drain for this runs into the frame rail and cannot be cleaned out, thus resulting in water staying trapped in the ductwork and causing corrosion. I have since drilled a hole in the vehicle interior plastic ductwork where the drain is to clean it out (and subsequently plug)
Rear window wiper has stopped, likely due to corrosion on the wiper shaft.
Catalytic converter had to be replaced when purchased.
Replaced most seals between 160-190,000 to include: front and rear pinion, rear main, intake, exhaust, front and rear T-Case, rear transmission. These parts wear and replacement was expected.
Radio had to be replaced, amplifier was damaged in A/C replacement (don't ask how)
The Grand Cherokee is absolutely a great vehicle if you are a car aficionado and have some mechanical aptitude. If you expect every little electrical gadget and plastic piece to operate as if it were new then you should look elsewhere.
With a little proper attention and regular maintenance I've put over 30,000 hard miles on my ZJ in the last year. It's been driven hard off-road and fast down rough dirt roads. These same roads have destroyed Camaros, Eclipses, Miatas, sedans and even pickup trucks with their washboard turf in less than 6 months. All of my Jeeps have worn just fine.
The 5.2 V8 has good power, it's a time proven reliable engine and well suited to the Grand. The NP249 T case has also been great, especially on road with the full time 4 wheel drive. Someday I may have to replace the viscous coupling, but with 200,000 it still works fine.
Overall the stuff that really matters is very reliable. The unibody work great, the suspension and drive-train hold up. The V8 shows little sign of wear. No other SUV I've had has held up this well.