Most enduring audio purchase

Now that my Talon Khorus speakers are gone, and not counting tweaks like the Zerostat and BDR Cones, that leaves me with my most enduring component being my Miller Carbon Turntable. https://systems.audiogon.com/systems/8367
Born early 2003 and still going strong.

Vandersteen 3A Signatures. 

Although, they are not currently active, but occasionally get used for one reason or another, my Polk 5 Jr’s I bought in 79-80...can’t remember exactly. I have none of the old equipment from that time except the Polks, and will probably have them til I die.

I get 'The Nervosa' from time to time, but whether it's just because speakers are a pain in the balls to sell, move & change or it's even harder to find the right speaker, I find it's the speakers that last longest, followed by amps.
It takes me a longtime to both research & find the *right* speakers and a very long time to commit to changing them.
My Vandersteen 2Ci's, Thiel 3.5's, Maggie 3.6's and B&W 802 Matrix's over have seen *dozens* of luscious and a few not so luscious preamps over the last 30ish years. I'm a preamp whore. Love a few different sounds. Love tubes, then I love leaving a nice, hot SS on 24/7 again- it's shameful.
I've probably had a half dozen preamp switches in the last three years. I'm in the middle of one right now.
Amps, again, less than a half dozen- that's another thing. When you get a good one, you just stick with it and dick around elsewhere. Same for DAC's. I hung on to my CAL Sigma 2, which was so 12AX7 tube rolling responsive, for a very long time. I still think about how much pleasing music I used to get through that beauty. I might even retro digi-fit a new one. That was a lovely DAC.

I bought a pair of Proac Studio 1s back in the mid-90s and have had no reason to part with them - amazing high end from my admittedly limited near-field monitor experience...