Okie, from my experience: Summing it all up on 4x4's I used.
1992 Nissan Hardbody 2.4.: Low on power, Marie Biscuit wheels, but tough as nails, and really good offroad. Fuel Consumption fair, about 8km/l. Only problem was the wheelbase, so straddling was sometimes a problem. Not too comfy, but lekker.
Series Land Rover: Conversions, V8 Landy motor, sealed fuel system, Salisbury diff's, Fairy overdrive(A waste of time), Took Fairy out and changed ratio's from 4,7:1 to 3,54:1, snorkel. Unstoppable, uncomfortable, unbreakable. Fuel consumption,
But great fun.
Nissan 2,7 Diesel 2003 model. Comfy, tough, but underpowered. Still great offroad though with fantastic fuel consumption.
Toyota 2,7 petrol: Crap allround.
Jeep Cherokee country 4.0l straight 6: XJ series. Great on and offroad. Great wheeltravel, tough, comfy, and best of all, fuel consumtion fantastic at 10km/l.
Landrover 130DC TD5: Comfy enough, I am a short S^&#*t, fuel consumption great, fantastic off road consumption, Best Offroad ability I ever encountered. All the mods, airconCD etc. Slow on the open road, but you can tow a house behind you, extremely powerfull. The best in my books for the serious adventurer.
Now, Jeep Grand Cherokee, 4,7l V8: Very comfy, but not tested offroad yet, only a few flashfloods, and rock-climbing. Will elaborate later.