i agree with justin. i have a 96 xj with 190k, when i bought it, it was completely stock. i put on a 3in rough country lift with no problems. i had a 2002 wrangler with that same 6cyl with all that emissions bs. it never ran right. nothing but problems. My 96 is the first year for OBDII and it is awesome. no problems ever. I had it covered in mud to where no color was showing and it ran like a champ then drove 2 hours home the same day.
the earlier cherokees like 88-90 are good too because of the renix fuel systems. they easily get 20mpg+ on the highway.
look for rot on the rockers, rear 'trunk' deck and especially near any leaf spring mounts. (mine is rotting on the front leaf mounts and there is no way to stop it
)
everyone says they are expensive but not really if you know what your doing. i dd mine and when i can i beat the crap out of it off road, BUT i also change the oil, diff and trans fluids every time i get in high water. straight 6's eat spark plugs about every 30k for some reason.
also watch for 'death wobble', with a lift you need a really good alignment and make sure the worn parts are replaced asap.
other than that its the best suv/truck i have ever owned and i am not going to sell it. just run it until the body breaks in half.