Science kit recommendations please

[Stitchosaurus]

I want to get DS a science kit for Christmas, I've had a scout around online but everything I've seen has very mixed reviews and doesn't seem particularly worth the money (need to buy ingredients before using, flimsy, over too quickly etc.) - has anyone bought one that they'd recommend?

DS will be 5 but I'll be happy to help him out with stuff if the better kits are aimed at older age ranges.

My DS 's now 7 and 9 have really enjoyed the John Adams hot wires snap electronics set they got last year. I don't know why it's called that as there are no wires, just plastic pieces that you can snap together to make different circuits. They have made all the circuits in the book and enjoy doing their own thing now.

I think a 5 yr old wouldn't need much help with it.