Tiny Swiss army knife with scissors, tweezers, blade and file. Use it constantly. ~$15.

Digital multimeter. Diagnose basic electrical problems in house, car, etc. ~$20.

Chemex coffee maker. Best way to make coffee. (Was a gift.)

Cuisinart chef’s knife, ~$30. Still a cheap one, but good enough to make preparing food more of a pleasure.

Plastic organizers for SD cards. Multiple little compartments with lids. ~$10.

GigSky sim card: internet access anywhere in the world. ~$30 for card + various short-time plans that you buy as you need them.

Lindstrom Rx8150 cutters. https://uk.farnell.com/lindstrom/rx-8150/large-micro-bevel-c...

EDIT: I guess I should say a bit more.

If you cut a couple of wires every day you don't need these. Any cutters will do. If you have a wide range of wire that you need to cut, from very fine copper to not so fine steel you don't want these, because they'll break.

But if you're spending all day, five days a week, cutting 7/02 or component leads, then these are lovely. The edge is sharp and stays sharp (so long as you don't do stupid things like cut steel), the pivot is smooth, the pivot is solid (my cutters had no wiggle after years of heavy use), and the handles are comfortable. The spring is plastic and clips into mouldings in the handles, so it's a part you can maintain.

Swissgear/Wenger carbon backpack (86€). It's been almost four years and it basically still looks like new.

Raspberry Pi for a Pi-hole

Leatherman Micra mini-tool

Global Entry

TSA Precheck for those who travel domestically. One of the best purchases imaginable.