What is the most recent brilliant tool or model making accessory bought and most often used?

[Bugatti Fan]

John,  the Moore&Wright Micro meters  I have are in  Imperial (Inch) standard that was still the norm over here in the UK until going metric in the early 70's.  I was brought up on feet and inches like many old timers like me over here.  But have to admit that Metric is easier to use overall. However, I still think of lengths in feet when describing longer items like wood.