Best 4 x 4 for driving a round the world trip in?

Driving around the world? I don't think they make a 4x4 that can do that. Most don't float.

In most African safaris, you see them using old Land Rovers or old Toyota pickups. The reason for that is that parts for that are readily available everywhere. Above all when going for rugged terrain, you would need to consider that everything will break, so you will inevitably need to fix it. A Nissan Pathfinder is a luxury urban 4x4, not really all that rugged, good for maybe handling snow and rain in paved road: and you definitely wouldn't be able to find parts to repair it in most third-world countries. As far as rugged goes, perhaps a Jeep Wrangler, but again, outside of North America, parts will be hard to find. I'd stick with Toyotas maybe.