We love our neighborhood park in UCity, called Mooney Park or Jackson Park -- on Jackson at Delmar. It's nothing special, but you often meet interesting and nice people there. Two great STL County parks for young kids are Tilles Park off of McKnight at 9551 Litzsinger (
http://www.co.st-louis.mo.us/parks/tilles.html) (has some water play, neat equipment, and winter light show) and Faust Park with its carousel, great playground, historic bldgs, the Butterfly House -- is not to be missed (out on Olive in the County -
http://www.co.st-louis.mo.us/parks/Faust_home.html). In Forest Park, the playground just behind the History museum and next to the visitors' center is also great fun --good esp. for toddlers with its rubbery ground.