As a contrast, the 4 halls of tanks are part of why I love Shedd so much and why I have voted for it. For me the collection is not just great, but can hardly be compared; it is a taste of what may well be the continent's largest species collection, with a wide taxonomic and geographic range of native and exotic freshwater fish, marine fish, dozens of herps, and invertebrates. So many aquariums focus on making pretty displays of just popular or colorful fish that Shedd's decision to keep and utilize its historic gallery displays feels like a blessing to me. I can agree that many of the tanks look dull and uninspiring, but for me the collection is more than enough and I like that there's no gaudy or overplayed attempt at beautifying them. It's an older style of exhibition, but one that I think is increasingly undervalued. Of course, more immersive exhibits are also essential and ideal I think - fortunately, Shedd shines here too with Wild Reef and Amazon Rising.
I also voted for Saint Louis Zoo, as well as Congo Gorilla Forest (which I have yet to see, but from what I've read and heard it still holds up as an exhibit masterpiece two decades after opening).