A 3D-Printer, I thought I just play around with it and get bored, but you discover so many things that you can do!
The handle on the fridge broke? Print new ones. Need a Flowerpot? Just print one. The router needs a wallmount? I have one ready in a few Hours.
Also I can watch it print for hours, very fascinating and calming.
With the difference that you are allowed to buy and consume beer and wine at the age of 16 (hard liquor with 18).
So the whole "protecting the youth"-spil is idiotic ...