We are upgrading Adam to harder puzzles - real puzzles! We have two wooden 12 piece ones that he is really liking and can pretty much do on his own. We just got this "floor puzzle" of dinosaurs (which he loves). It is 24 pieces and 2 feet by 3 feet. Adam is already in love and it will take him some time to get good at it, which is a good thing as it will be a challenge. Notice though we are doing the "floor" puzzle on the table...we have to watch out for Andrew sabotage! Even the little wooden puzzles...seriously, Andrew knows instantly and hones in! We tried the bed, but its too "squishy" as Adam can't sit still enough.
As a note, our wooden ones come on a "board," which is great as it gives him the dimensions to start with AND he can do it in the car! He'd been pulling the "I need help" on the first one...well, he wanted to take it in the car and I let him (thinking I'd be pulling pieces out of everywhere) and he's working back there...I turn around and he did the entire thing with no help! He so was faking needing help!