I love zoos. The modern zoos where we are more educated, where we take more care over our animals from food to enrichment for them. I like also that our zoos are doing conservation. Through breeding we are returning animals back to where they should be, in the wild.
I however do not like zoos when they are crowded.
My way round this, is to go on a cool day, when the weather is mizzly. This cannot always guarantee a quiet time.
My other way is to pay for photography experiences. Choose small zoos. That way you will find they have down time, so instead of paying for an animal experience and only seeing certain animals. A photography experience will give you a wide range of animals, if not all.
The other thing about photography day, you go around with staff, the animals trust them and will be more relaxed when they see them.
You also get a better chance of eliminating wires.
Here is this fella proving he is the majestic , looking down on us all.