It must be a thing, not a person or animal or plant. You must use it at least five out of 7 days a week…
For me it’s a wind up watch. It’s simplistic and it works great. My grandmother got it before World War II.
Beautiful! For me, it’s my purple Game Boy Color.
My cooking utensils, which my mum and dad were given as a wedding present.
My alarm clock. Must be almost 20 years old now.
Actually, the wooden nightstand next to the bed: my FIL made in shop class in Highschool. He would have been 83 this December, so, 67 years old?
A Droll Yankee bird feeder that belonged to my parents. They must’ve bought it 15 or 20 years ago, and the thing is nearly as good as new.
A ring that’s about 60 yrs old.
On a weekly basis, I use a light meter that’s older than I am (48).
On an about a monthly basis, I have some wood working tools that are over 100.
On a regular basis, the only thing older than maybe twenty years is my great-aunt’s desk. Goodness; it must be close to a hundred years old!
My audio amplifiers from the 1950s.
My wife.
First thing to come to mind was the comb I use after washing my hair; it dates back to college, I think 1974. It’s just a pink plastic comb, if I had realized I’d be using it for the next 40 years or so I might have given more thought to picking it out.
Well, the obvious answer is the house. It’s Victorian. 
My computer “desk” is a very old table out of a bar in Jackson, MI. I was told it was from about 1920 or so.
It’s wood, decoupaged with newespaper articles, and heavily varnished. The most recent newspaper date I can discern is July 13, 1913, a story about a train wreck on the “Michigan Central” line which killed several people.
I have some pieces of jewelry that are older than that, several books from the late 1800s and probably some other old stuff, but the desk is the only thing I use daily, pretty much.
We have several pieces of antique furniture around the place, and the kitchen has cast iron that was my grandmother’s.
The house. 1958.
That’s when my house was built! (I was built that year too. 
)
My dining room table. It’s nothing special, not some fancy “antique” but my dad remembers it being his table when he was a kid so I’m guessing it’s around 60 years old.
I wear a rind every day that belonged to my mom. She was born in 1925, and got it for her 16th birthday so…1941, making the ring 70 years old.
My house was built in 1953.
My parents bought my art deco bedroom set when they were married, in 1938. Though I’ve replaced the bed, I still have the two dressers, night table and mirror.
And the house was built the same year.
My Q Nobatron QR40-2A power supply. It’s got to be 45 years old…
My house, built in 1914.
Then me.