Ask HN: What are best gifts for smart kids this holiday season (2017)?

I recently got a request to help good friends of mine come up with some gift ideas for their precocious 5 and 2 year olds.

One is a "take it apart and figure it out" type (5yo) and the other is a "lots of imagination, wit and storytelling" type (2yo).

So what are the best games/toys/media either on the market or coming to market this holiday season to encourage the development of these kinds of children while keeping it fun and engaging?