Oh dear I must be out of touch! My way of buying a present for any of the grandchildren is to ask parents for ideas but also to think "what would help the child learn next?" My presents are usually "educational".
Board games for counting (and social) skills, a watch or clock to help them tell the time, shopping till for money skills, lots of books, a volcano kit, chemistry set, art and craft materials, a butterfly farm with live butterfly eggs, a subscription to children's Aquila magazine.
The presents are usually "successful" and enjoyed and help develop an interest in something.
Am I a bit too arrogant - thinking I know best?