What's the best and/or favorite piece of equipment you've owned? And do you still own it?

Tandberg 1055 receiver from mid-70s, manufactured in Oslo, Norway, it was one of the top receivers of the day;Scandinavia's answer to McIntosh. Was still going strong when I had it fully overhauled and upgraded 6 years ago. Visually it is almost dead mint. 
    It's powering my 2nd system. Love the looks, and  its not embarrassed sonically by the higher end separates in my primary rig when I've installed it there. Its always had a place in my heart.
     

I’ve owned a lot of different components from many companies in my life. So obviously they don’t count.   Speaker-wise, I’m a Maggie Man through-and-through, but I’ve upgraded up the Maggie line a few times now, so I can’t count them either.
I do have two old friends that I will never sell. A pair of McIntosh C-20 preamps. They’re both about 60 years old. I’ve owned them for almost 50 years. They both have been restored and upgraded twice. The last time by Don Sachs. I’ve had them tested and the specs now exceed the original specs by a nice margin.
My C-20s are in a quadraphonic system. They Each sit just before the front and rear channel amps and are restricted to a line-level input coming into the Aux inputs, and then stright out to the amps.
Basically, I use the C-20s for l-r balancing and volume control of each amp and to get that sweet tube sound they put out. This was in place long before the term “tube buffer” came into vogue.
I still think they are the coolest looking preamps in the world IMHO and as I said, after almost 50 years together - they’re like two old friends.
Tim

Dali Helicon 400, Sony TS 999ES SACD player. 

My Berveridge (Roger Modjeski, RIP) RM-1/RM-2 Preamp, since 1981.  Still amazing after all these years.

After many years  in audio and going through so much equipment, I can't say I miss any particular piece of equipment. My present setup is best I've had, I expect future changes will also be upgrades. At this point in my audio evolution I find I'm no longer nostalgic over past components.

If I was to wax nostalgic about any one particular piece, it would probably be recalling the experience of hearing my CJ MV55 tube amp after many years of exclusively running SS amps. Twenty some years later, tube amps only for me. Also, still own the CJ amp, likely will never be used again as Its bettered by all my present tube amps.