I'm stuck at what to buy Em lol

We went nuts at Christmas and he has heaps of toys already.He has a heap of the FP Roll-around range which he loves, a car walker, a trike, toy phone, blocks, FP Learning Puppy, trains... he loves playing with it all but at the same time I don't think there's any challenge in it now. So I want to get him new stuff but it all seems the same. He loves his shape sorter and making noise lol.

I'm actually finding that the more expensive stuff seems pointless. I'm also finding the stuff meant for 1 year olds seems to basic but it then jumps up to 2 or 3 plus and has small parts and is too advanced for him lol.

I have bought him a cute music set that has a drum, tambourine, maracas and harmonica (lucky mum lol). I've also got him on those peg thingos which has the plastic rings in different sizes that you put over the peg? (Did that make sense lol?). I've got him a few DVD's - he loves Hi 5 lol.

My only other idea is one of the old wooden toys which has the bent metal in crazy shapes that has the beads on them! I used to love playing with them. But I have no idea where you would get something like that from.

So does anyone have any ideas or suggestions for some toys that will challenge him and he won't get bored with?