I've had to replace 4 of 6 u-joints (front axle among them), rear seat belts, rear seat mounts, PCM, rebuild the AX-5, many dash bulbs, steering shaft, a motor mount, front axle seals, oil pressure sensor, rear exhaust manifold stud, battery, a few tie rod ends, thermostat, and probably a few other things I'm forgetting right now.  My YJ also has rusted floorboards.  Amazingly, besides the PCM replacement, it has always run very well (only 85,000 miles) and when I redid the valve cover gasket, saw that it has no sludge up there.  I think the previous owner used it pretty hard but did regular oil changes nonetheless.