Back on topic...
I want Predator 3 to go back to the jungle, or at least a forest of some kind, or maybe even a desert. A lone group of humans, checking out why more and more of their townsfolk/fellow villagers have gone missing, and finding out something disturbing. In the meantime, you have two Predators: A bad blood one who has no honor and randomly kills, and a Predator hunting HIM, but not being scared off killing humans either. No teamups, make the Predators symphatic (establish a relation between the two; are they old rivals, enemies, friends, maybe even family, a son send to hunt down his deranged father?) but not TOO symphatic (they're both willing to kill and do so while thinking VERY lowly of the humans).
Keep it simple, but well directed, with good action, actually scare, plenty of mystery, well established character relations and humans dealing with both the unknown and nature itself, be it a desert, jungle, forest, whatever. No need to make it a big budget sci-fi extravaganza...
Oh, and for the love of god, go back to the Predator's routes and make them tribal hunters, not heavily armoured and hi-tech warriors. Even Wolf was guilty of that...