The very simple protector that keeps the cats from turning off my computer by stepping on the power button, while leaving the button itself accessible.

I printed an ikea pegboard holder for my paper towels. It’s in use every day

Miniature buildings, trees, walls and terrain parts for my Dungeons and Dragons campains.

Sink cover to catch bits. Every time I move to a new place, I print a new one. Just a simple PLA one lasts literal years. I had my last one for close to 4 years of daily pouring down boiling soup and other crap until I poured some 35% vinegar accidentally.

I’ve printed some basic gridfinity bins (the vase mode ones are super quick and sturdy enough for what I’m doing) and baseplates.

I also custom modeled a hook for my headset that would only work for my specific desk.

First thing I ever printed was a spout to replace the elephant trunk on my Rancilio Rocky coffee grinder. It allows me to use the grinder with basically 0 ground retention so it was a huge improvement and allows me to accurately use the grinder for single doses. https://www.thingiverse.com/thing:101392

Another thing I made were some spacers to correct alignment on the freezer door of my French door refrigerator. They’ve been working great for years now and keep the door seal in perfect alignment. I custom made these and they’re unlikely to be useful to anyone else.

I also am very fond of some wire organizers I use for managing USB charging cables so they’re not a jumbled mess. https://www.thingiverse.com/thing:5340635

I printed new treads for my beach cart in TPU.

The single most useful print is just a simple cylinder to repair a broken knob on a nearly brand new kitchen stove. A new knob cost $35 at the time and had a 2 month lead time from the factory, (it was during the covid lock down).

It took longer to turn on my computer and start up my CAD program than it did to design the repair part for the knob. 30 minutes later, I had the sleeve printed and super glued over the broken part and the knob reinstalled on the stove.

That’s been 7 years ago, the repaired knob is still there and in use daily. And one more knob got the same treatment. It probably took less than 10 cents of PLA and electricity for both repairs.

Drops for drones, drone parts.

New interior door handle for a john deere 450clc excavator. Red pla, so far, has outlasted the original

With the exception of crap for the kids and cake toppers, everything I print is to solve a problem I/we have.

Here are the gridfinity drawers I designed and printed for under my desk. https://www.printables.com/model/1129785-gridfinity-under-desk-drawer-system

I’m about to start printing triple stacks of these to put better drawers into my IKEA KALLAX shelves than the ones IKEA sells.

Not sure it’s the most useful in a day to day sense, but was great for a d&day darksun campaign. I have got quite a few grom gloomykidminis, great quality

https://only-games.co/products/mekillot

A AAA-battery to AA-adapter. I randomly had 50 of the smaller ones lying around, so it really came in handy.

Can’t share a link, but there should be dozens of this kind of model on any site. “Can’t”, because the model I grabbed was definitely among the worse ones.

Most useful as in something I wouldn’t have otherwise is probably some gridfinite thing. SD and usb stick holders maybe.

Most used is probably a plain headphone hook for office. Daily use and storage for years.

Most saved time and money? Jigs and dummy parts at work which have helped avoid more expensive processes and mistakes in more expensive processes.

Earbud Charger Charger. Put your earbuds in the charger and put the charger in the charger charger and the charger charger keeps the charger charged.

In other words, an earbud case holder. The earbud case can charge wirelessly so I put a wireless charge coil behind where the case sits. I put a piece of metal on the back of it so it sticks to a magnet mount in my vehicle but I plan to 3D print part of my dash with this built into it.