A very interesting question posed, at the start of the thread. And time for me to stir the pot again, after a year!
I've owned a 1988 4.2L Land Cruiser (60 series), a 1986 Pajero (LWB), a 1952 Willys, a 2000 4.7L Jeep Grand Cherokee Limited, a 2000 4.6L Range Rover HSE, and a 2003 4.5L Land Cruiser (70 series). I think that represents a fairly broad choice of vehs for comparison.
Without a doubt, the 70 series Land Cruiser is the best off road vehicle I have ever owned. Followed by the Range Rover, the Willys, the Cherokee, the 60 series Land Cruiser, and the Pajero...in that order of descent. These, from the vehicles I've owned. However, it'd still rank better than the Defenders, the Discoverys, the Patrols, the Titans, the Hiluxes and the Yukons I've had the pleasure to drive.
I'd like to state here that simply saying "Land Cruiser" is a bit of a misleading statement. Not all Land Cruisers actually ARE the best off-road vehs out there (especially in Pakistan, where the choice is limited). The 200 series Land Cruisers, the Lexus series et al, are simply poseurs; oversized cars that have 4WD and fat tyres. Personally, I don't count them as off-roaders at all. I'd consider them toys for the man (or woman) with lots of moolah; whose off-roading experience will be limited to engaging 4x4 in the driveway leading to his (or her) billion rupee farmhouse.
So, back to the original question. Is the Land Cruiser the best off-road vehicle out there? Yes. The 70 series TLC probably is (specifically, the FZJ-79 pickup).
Why? Relative cost. A 212 HP I6 engine that just doesn't quit. Huge amount of torque on hand. Insane power to weight ratio (for example, my Range Rover churns out 222 HP, but weighs twice as much as my 212 HP FZJ-79). Incredible gearing. Terrific ride clearance. Maintainability. Ruggedness (in most types of terrain). Reliability.
Just my two cents worth.