Lincoln Park Zoo
Sure, Lincoln Park Zoo is free, but for a $90 household membership you get two free parking passes (up to a $70 value) and discounted parking for other visits, invitations to members-only mornings, members-only night for ZooLights with shorter lines for photos with Santa, 50 percent off stroller rental, 10 percent off food and, best of all, free or reduced membership at more than 100 other zoos in the country.
Brookfield Zoo
At Brookfield Zoo, a Plus membership ($125 a year) includes free admission for the family plus one guest each visit, eight free tickets to attractions, free parking at the main entrance and free admission to the Hamill Family Play Zoo. It pays for itself in just two visits.
Shedd Aquarium
The colors and movement of the fish and the playfulness of the penguins and belugas fascinate even the youngest of babies.
A one-year membership at Shedd for $195 might seem steep, but daily admission for a family can add up quickly. This membership pays for itself if you go just twice (Shedd is a good go-to to save your sanity, so you likely will go more often) with free admission, free entry to all exhibits, tickets to aquatic shows, exclusive member events, early notices, discounts on learning classes and programs, discounts on food and stores and reciprocity with aquariums and zoos nationwide.