The Denver Children's Museum was the best museum we've been to (for children).
We went while they were having an Easter celebration. There was a rabbit handing out goodie bags, and you had to follow clues to get more 'goodies'.
There's something for all ages to do here, we (my husband and I) had a wonderful time with our two boys. They have an infant/toddler play area, and a special little spot for those who can't crawl yet (or are learning!).
Aside from the young children’s activities, they have a fire truck exhibit, arts and crafts, a grocery store where the kids can 'shop' and tons of other fun stuff.
We easily spent 3 hours here, and could have stayed longer! It's well worth the price, and adults will lose themselves and play like kids again. We enjoyed our trip, and I would definitely recommend this to any family.