This part may not help too many others (if any) but it has served me well. My wife's dish rack broke and my 3D printer came to the rescue. I know this is a cheap dish rack that isn't worth rescuing but it would just add to the world's landfills. With a very inexpensive part, $0.16 (estimated), and a little effort, the dish rack was put back into service.
This part showcases the real world application of 3D printers.
I basically created a cast, (not out of plaster but rather in PLA) for the broken arm. I sized it 101% of the actual size and it fit perfectly. In fact, I didn't even glue the broken part because it's holding so well. As you can tell from the picture, I didn't print the part ideally to maximize strength but it has been holding up well. Should it ever break/fail, I will reprint it with a different orientation to maximize part strength.
Hail to 3D printers and all the useful things they make!
I did print this part at higher speeds than normal because the part's finish and quality didn't matter to me. My wife prefers function over finish.