For a tourist Central Park is probably the easiest to get to. Since 2007 they did open a solid pair of snow leopard exhibits and renovated the old polar bear exhibits for brown bears.
Central Park has sort of turned into a Bronx surplus collection. It still has some cool stuff not kept at the other collections, but if probably the least unique out of them all at this point imo. I've done the zoo and natural history museum together in a day before, though, which might be of interest. I've also paired CPZ and Prospect Park Zoo before...
Thanks to you both for the advice. I'll be sure to look into all of those options before making a decision.
So many, many sea lions! There are other pinnipeds people!