I think it's hard to beat Safaripark Beekse Bergen here. Even their second elephant outdoor paddock is about as large as entire smaller elephant facilities, and the main paddock offers a lot of space, which for elephants is definitely a necessity. The mix with Hamadryas baboon is also rather nice. One could perhaps argue that the main elephant paddock looks quite barren, although it still offers the elephants all of their necessities. The indoor housing at Beekse Bergen was improved a lot with the construction of the barn shown above.
The facilities at Monde Sauvage and Pakawi Park/Olmense are barely above the legal minimum and are honestly pretty bad. The outdoor paddocks are rather small, if not too small, and while the indoor housing at Monde Sauvage is off-show, I think we can assume it won't be much better than at Olmen.
The outdoor exhibit at Pairi Daiza is pretty decent, especially for former circus elephants, but the indoor housing there is off-show, so it is difficult to fully evaluate the quality of the exhibit. Compared to the other exhibits the level of difference in elevation sets this exhibit apart from the others.
The facilities at Ouwehands I think are rather decent and I think I would put them in second or maybe third place after Beekse Bergen.
