PBSKids Cyberchase has lots of games that get kids to think creatively to solve problems. There are games where you have to invent things, estimate, or find patterns. There's also a crazy game show with the twist that you need to find the example that proves something is NOT true.
There's a kernel of learning in each game too, making it ideal for parents and teachers who want kids to have fun and learn at the same time. You'll find a list of all the games on this page.