My DS just turned 2 a couple of months ago, and our puzzles are now way too easy for him. We have the knob kind for ages 2+. He still enjoys them, but he can complete them in mere seconds. He's got really great fine motor skills and is good at pattern recognition. What puzzles would you recommend next? There are so many out there that I don't know where to begin. What has worked best for you?

You'd think that since this is my third child, I would know about these things. My girls never really liked puzzles, though.