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.
My computer, Alienware Aurora R1 (Core I7 - 960) that I broke into my savings to get back in 2010. I use it everyday. Last year I upgraded RAM to 32GB, got a second hand GTX 1080 Ti, and just two months ago I swapped the HDD for SSD.
I also use a 43' Samsung 3D TV that I got back when it was all the rage.
Glad that yours is holding up so long. I bought a R2 around that time and keep the chassis barely 2 years. Some designer thought it was a great idea to put a single vent GPU 1cm above the HDD, resulting in regular overheating of the GPU. I extracted all the components and moved them to a new chassis. It died 4 years ago.