id steer clear of Discovery's if i were you. personally, i do like them, but you'd have to be lucky to get a decent well looked after example, plus they seem to command a high premium for what you get, still, i do like them. then there is the 90 or 110, but i think they arent much better and certianly not fun to drive as far as i know.
there is the Fourtraks, ive had one, and i loved it apart from it being aweful on the road (see Discovery!) but they are VERY reliable. mine was in bits, i tell you it was a bit of a tip, but it never broke down ever, took me to south wales and back plus a few thousand miles with only one bolt holding the power steering box on, i tell you, they are rock hard machines. only problem with them, is they are small, even the long wheel base is small and only three door. but you'd have no trouble off road, they are VERY simple too, very basic but everything clunks into place as it should.
after that, everything is out of my reach, so cant really advise on Xtrails or HiLux's etc, but thats where id be looking, especially hi-lux...