Jungala is a real winner.
The tiger and orangutan habitats are AWESOME, no other word for it. You could spend hours there. They have very large indoor viewing areas with enormous plate glass walls, even a glass floor at the orang exhibit. I just wish they'd come through more often and clean the hand and face smudges off the glass!
The tweener play area is also extremely well done, right up there with Land of the Dragons (also at Busch) and Camp Jurassic at Universal's IOA.