I'll focus on Smithsonian's National Zoo. I feel most exhibits could use some improvement.
Asia Trail:
Poor viewing for sloth bears and fishing cats could be improved.
Something needs to be done about the former Japanese Giant Salamander habitat. I think it needs to be totally renovated, because even when it had a salamander in it, the viewing was poor, and the lighting was poor. The glass is also slanted at a weird angle for even worse viewing.
Use the unused space for something, anything. Indian rhinos, Przewalski's horses, onagers, an aviary, dholes, whatever. It's a space that would be good for any exhibit.
Bird House:
Poor viewing and collection but both will be (hopefully) better after its renovation into Experience Migration.
The kiwi exhibit just doesn't work.
American Trail:
Viewing for bald eagles could be better
Ravens need more enrichment
Small Mammal House:
Naturalize some enclosures
Some species are in enclosures that are far too small.
Big Cats:
The exhibits are basically just concrete terraces with some dirt on top. Only one of the enclosures is lush, and all three are pretty ugly.
Think Tank and Great Ape House:
Pretty much all of the orangutan enclosures are too small
The O-Line is great, but also really ugly
The gorillas have poor viewing, especially outside
Reptile Discovery Center:
Change the name. Please.
The entire inside could use a redesign- museum-like displays and a lot of enclosures are too small.
All of the crocodilian exhibits, except the one for American alligator (so a total of 7 exhibits for 5 species) need a redesign.
The outdoor reptiles (Chinese alligator, tomistoma, and Komodo dragon) need bigger exhibits and the two crocodilians need exhibits that are actually outside (at the moment you just look into indoor enclosures).
Amazonia:
Better signage, throughout the entire building.
More bird and monkey species, with a few new furnishings for them.
Kid's Farm:
I never really go here and if I do, I just walk through it and I don't really pay attention. It seems decent though.
Gibbon Ridge:
Bigger habitats
Elephant Trails:
A refurbishing of the two small habitats.
Let the herd choose where to go.
Bring in a bull (but let him have a good exhibit, unlike so many zoos).
I think that's all.
