I brought my boyfriend here for a belated birthday celebration. We went on a Monday and were able to get discount tickets through Amazon Local. Coming from the Chicago suburbs, I was pleasantly surprised how easy of a drive it was to get there and how quiet the zoo was. Brookfield or Lincoln Park Zoo is usually busy with some class trip or tourists visiting the area. But we got a clear view of all the animals and weren't being run over by agitated moms and their strollers.
I like how some of the habitats mix various animals together instead of separating them. There is some construction going on, and the zoo appears to be making some nicer exhibits for the panthers and sea lions. It's also cool to see the baby animals in the nursery because a lot of zoos usually keep them out of sight until they are ready to be put in the habitats.
There are some zoo animals you can pet if you get close enough and don't have to pay extra to do so. You do pay extra for rides, a train, or the lift that goes above the park, but those are all optional and you can get around find without them.