I've bought 3 and they're all still running:
1995 Grand Cherokee Limited w/V8: 167,000 miles on it and nothing but regular maintenence on it. It's my daily driver.
1994 Grand Cherokee Limited w/V8: 105,000 miles on it no major problems
1994 Cherokee Sport w/V6: fantastic engine, no problems.
Also owned a 1989 4 cylinder Wrangler that I loved and put over 100,000 miles on before I traded it in!
I wouldn't hesitate to purchase or recomend Jeeps to anyone - I've had nothing but good luck with them. (knock wood!)