So where's the context?
In who's eyes? What standards are they judging by?
It's entirely possible for any zoo to look absolutely spic-and-span to the untrained eye, but have horrible animal care. In order to truly judge any zoo, you absolutely, positively, HAVE to know as much about exotic critters as possible, and how the zoo you're looking at operates in terms of animal environments, enrichment, diet, vet care, etc. It's called "context."
Some examples.
Greater Vancouver Zoo: Looks great from the outside, has a slick web site, makes a big thing about being CAZA accredited. If you know nothing about exotic animal care, it may even appear there's nothing wrong. However, this is also the zoo which put Cape Buffalo in with their zebras, tried to cover up the resultant stress-induced death of all four said zebras, AND which continues to employ a so-called "master falconer" who has cost 11 of his birds their lives in a three-year span.
This is also the same zoo which has been under investigation by the BCSPCA and CAZA -- multiple times! In fact, they're still under investigation even as I type this.
Alabama Gulf Coast Zoo: Tiny, never been accredited by anyone I know of, has all the appearance of a typical "roadside" attraction from the outside.
Yet, this tiny zoo has some of the most dedicated staff and some of the best animal care I have seen ANYwhere, hands down! Rarely have I seen animals which are better fed and cared for.
My point is "10 Best" or "10 Worst," or however many you're rating, is meaningless without a broad context. The author of that list seemed to be fixated on two basic things: How old the parks were, and how many animals are in their respective collections. That's hardly enough to even begin to consider "best" or "worst."
As a side note -- That's a nice photo of a bald eagle on the blurb about the Smithsonian. Too bad the bird also looks like s/he needs some serious beak coping (necessary raptor care in any captive environment).
Happy travels.