My own list:
Dinosaur State Park (Very large indoor trackway, and you can make a footprint cast during the summer if you remember to bring the required materials, also extensive exhibits, informative films, and nature trails).
Rocky Neck State Park (bring sunscreen, beach umbrella, bathing suit, towel, and lunch in a seagull proof container).
Bluff Point (same)
Stellwagen Bank National Marine Sanctuary
Acadia National Park
All of Pittsburg N.H. (Moose). Also the Fourth CT Lake Trail (Grouse, beavers) however beware of the CBP. This is a good place to bring your passport to because it is right next to a non ruined exotically French speaking part of Quebec that I may well find new favorite wildlife places in.
Any Fair with a good agriculture or wildlife exhibit, however I did once see a petting zoo where the lemurs should not have been brought (they were all clutching each other, terrified, I think someone complained/saw the light/both because I have not seen them since).
UCONN Horse Barn (look out for snotty UCONN Students).
Saco River, Maine
Fenway Park (the world's most fearless pigeons).
The Museum of Natural History
And a bunch of other places I probably haven't thought of.
Alas, I have not traveled much outside of New England. Whatever, I'm only 24.