We love OSC, and our 3 year old loves it most of a...

We love OSC, and our 3 year old loves it most of all. The new Kids Town is fantastic with excellent water table, great climbing structure, awesome stage with digital backdrops, and the vacuum scarf machine is super cool.
Upstairs has many of the staple demos and interactives you expect from a good Science Center. Science On A Sphere is great for learning about Earth and the Solar System, the Dino Dig is a good size and is always popular.
They usually have a main attraction that is swapped out fairly often. We've been impressed with these exhibits, our favorite was the History of Toys. Such an awesome exhibit, fun for the kids and parents. You always saw parents playing with their favorite toys right along with their kids, a sure sign of well designed exhibit.