What is the most useful thing you own. Around here it's the vacuum. Always dragging yard stuff in back door and dog hair is everywhere.
Too many things to pick just one. I would be lost without my washer & dryer, my refrigerator, my car...all important for different reasons.
I probably use my computer the most.
The modem gives us phone and wi-fi. Can stream TV, surf the net and call for pizza.
So many things, but my computer is most useful as far as entertainment, info and ordering things goes.
Still the computer, but I get you about the vacuum. Maxie cat doesn't even go outside, but the cat hair proliferates.
Probably my cell phone. I use it not only to play games, keep time and schedule things but also to order my Uber rides, check train schedules and buy tickets, listen to my music playlists, check my docs or password keeper for password hints, use an app to get a login key for my brokerage account and more. A couple of those things cannot be done on any other device.
My Swiss Army Knife for sure. Had it for over 30 years and is in my pocket always. (Except when I fly!) So many uses!