The best hyena exhibit that I have seen is the striped hyena exhibit at the Living Desert in Palm Desert, California. It has lots of places for them to dig and play in the dirt and good interpretation of why hyenas are cool animals. Most of the viewing area is indoors and through a glass wall so you can see them very close up. The Oakland Zoo has a spacious exhibit for spotted hyenas that is well vegetated, but it is at the bottom of a hill from where the viewing area is and the hyenas are hard to see and watch.
I think that not only are there no brown hyenas in the U.S., but aardwolves and striped hyenas seem to be on their way out too. The Living Desert had an aardwolf in a nicely vegetated exhibit that had good viewing, but they no longer keep the species. I think that Wildlife Safari in Oregon had brown hyenas at one point, but that was many years ago.
Thank you David, and it seems that Living Desert does have a nice hyena exhibit. I've seen 5 hyena exhibits;
Busch Gardens Tampa Bay- Best hyena exhibit I've seen yet. Spacious, great viewing oppurtunities, giraffes and hoofstock are in background, and the Spotted Hyenas rotate with African Lions.
Lowry Park Zoo- No longer keeps Striped Hyenas, but their exhibit was on a island with limited viewing. They used to rotate with Cheetahs, but now Cheetahs are out 24/7.
Bronx Zoo- A very good hyena exhibit, with several viewing oppurtunities and lots of space. However, the glass viewing could be bigger as it's basically just a small window.
Naples Zoo- They had 2 hyena exhibits; one for Striped Hyenas, and one for a Spotted Hyena. When I went, the Striped Hyenas had a nice grassy enclosure with space and trees, and the Spotted Hyena had a smaller, adequate enclosure. The hyenas rotated. Now that Cheetahs are in the zoo, the Striped Hyenas and Spotted Hyena rotate in the smaller habitat.
It's a shame that Aardwolves are in only one US collection (Cincinnati), and that Striped Hyenas are in limited numbers. I think that Aardwolves will disappear from the US once Cincy's Aardwolves pass, but I think Striped Hyenas will stay in the US, at least for a little bit longer. There are currently only 15 Striped Hyenas in the US. At least it seems Spotted Hyenas will be here permanantly. Lucky Europeans get to see all 4 of the hyenas.

Do any exhibits have any interactive features, like skulls or demonstrations showing the hyena's biting power?