What has been your most satisfying component?


I don't think I have seen this question asked so here it goes. Many of us tend to buy and sell looking for the ideal, the holy grail, what works best in the current system, or whatever.
What component (or components)have stood the test of time in your system? I've been through quite a few but some have stayed despite having bought their replacements and subsequently selling them. I'll share once we get a few posts to get things going.
nutella
My room treatment acoustic devices, for sure, followed by
my Magnepans 20.1 replaced with Analysis Audio Amphitryon and 1993 built Nakamichi MB1000 Music Bank CD transport.
I'd cry if something happened to my nad 4020 Tuner. Great sensitivity, selectivity, rejection in a steel hi-rise condo notorious for poor signal. Fortunate to have 2 wonderful stations, 1 with folk/acoustic/blues in the morning and the other with mostly all-day classical programming.
At this point, I would have to say my DIY 3 way speakers.

Sold my paradigm s8 and wilson sophia after I built these speakers.
My Rogue Cronus Magnum. I thought I was going to have to sell my speakers until I bought the Rogue. Then there's my NAD C317 integrated that's my stand by.