I've had Hiluxs and a Navara.
Hiluxs are frankly pretty fragile and vastly overpriced. The 3 litre diesel is good, the 2.4 and 2.7 petrol 4 cylinders are good, the V6s suck, the 2 litre, 2.2 litre petrol forklift motored things suck, all the 2.2-2.8 diesels suck. The big selling point in the pre '97 ones is the live axle front end, but in all reality that's no advantage until you're doing stuff that WILL break it in standard form anyway. They will go forever, yes, but nearly everything on them will be clapped out.
Have been driving a 4x2 '96 Navara for a while now (I call him 'Che') and everything in it is massively overbuilt compared to the Toyotas. The V6 petrol motor is great (and a mate's 2.4 petrol is much more refined and nicer to drive than a 2.4 petrol lux), diff in it is same as Patrols run (huge), gearbox is massive overkill, chassis are thick and deep channels, and overall it drives a lot tighter and seems more ruggedly put together than a similar era Hilux.
Another vote for the Navs. D21 and D22 are very rugged vehicles and come in a lot cheaper than Hiluxs. Some of the diesels may be problematic, don't know much about Nissan diesels.
Parts are cheap, primarily because they just don't smash diffs, gearboxes etc as regularly as Hiluxs do.