The last Predator film ever made was Predator 2. Everything else doesn't exist.
Even predator 2 wasn't very good..
See, I really like that film. It has to be one of the most unrelenting action films I've ever seen.
Besides, we get to see more cool things about the Predator, which are now all canon, I should add. Remember that disc (the one that was so poorly implemented later)? That was Pred 2. Same goes for the different vision modes, the spear, the netgun, etc.
And also, despite being a huge Arnie fan (I love basically all his films) I like that the series didn't devolve into JUST Arnie v Predator, but that it was a more general menace than that.