What item have you been using on a daily basis for the longest amount of time?
Sometimes I will use something and realize I've owned it forever. It's a nice change in our throwaway reality. I think my personal record is a bicycle multi-tool I got for one of my first bikes, ~25 years ago. Still have it, still use it. When it comes to electronic devices I have a Panasonic mini Hi-Fi from ~2005. Never felt like changing it.
I have a lot of things over thirty years old, but I can't say they've been in daily use.
For electronics, and daily use, I have a 13-year-old Toshiba 55" TV. It's basically a big, dumb monitor. Still works perfectly.
I have several nightlights I bought about ten years ago, maybe 12 years ago. They all still work and have been in the same sockets around the house since I bought them. They're the flat, greenish glowing disc kind.
I've had my coffee mug for at least 25 years, it gets daily use.
This may be cheating on the daily use, but I have two brown glass horse bookends. They've been in constant use since I was a kid. I don't know where they came from, they were probably my dad's, as he had a large book collection. So, at least 60 years.
We have a similar vintage 55" Toshiba TV. It would be nice to upgrade, but it's hard to argue with something that's worked so reliably. It's also nice to have a decidedly dumb TV...
I didn't even think of the TV. I bought a (then) top of the line Hitachi Plasma TV in 2006. It has seen daily use all this time. I can easily believe I'll get 20 years out of it.
Fun fact: the kids have actually probably watched it more than I have, and I had a 5+ year head start.