as far as 4 door wagons the G-wagon, 80 series and Defender are all fairly equal off road, all 3 are solid axle, coil sprung. The 80 and G are built to a better(much) standard then the Defender. THe Defender has a aluminum body as a +, so less rust. The G does not have the articulation of the 80 or Defender, but has diff locks(standard, with a few exception on older G's) so the G uses it's traction to make up for the articulation, 80 had diff locks as option. A diff locked 80 vrs a diff locked G.....the 80 would prolly be a bit better off road.
Parts are gonna be less and easier to find for the Cruiser, Defender is 2nd.......G is 3rd. Reilabilty........80 and G are prolly tied.
G has a beefier frame than the others. Defender......well it's English........nuff said
the Patrol is a good rig, similar to the above 3
Pajero is IFS, not in the same catigory.
Sami does not compare.
Rubicon, Hzj74, G-wagon 2 door and Defender 90 are similar, I would take the 74 anyday of the week, the G would be 2nd......not sure about the others 2....no interest.
Hummer.....too bloody wide but good for what its made for.
Unimog.......IMOP it's not in the same class, its bigger(thinking of a 416) than the above, in some cases a better wheeler.....if it fits, not nearly the comfort of the 3 above.
Tantra!!! now thats a badass machine!!! if you like 8 wheel drive and articulating cab
there are some Inveco's that are interesting but MUCH bigger than a 80.
am sure I fogot something.....
the above in just MY opinion

A cruiser or a G are what I would take......looking at the G-wagon this weekend.....might be in my stable or not?
John H