Did you ever buy that toy you wanted as a kid but didn't get?
I myself wanted one of those remote controlled air planes. I thought that's the coolest thing ever. Once I grew up and had the money, I never bought it.
When a good friend had a child I bought them a big Brio set. Every kid should have Brio.
My friend and his brother both do woodworking as a hobby, they made custom track, bridges, tunnels, and rolling stock. It's now a whole room in a house. It should last a few generations.