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

Ohm Walsh speaker owner since 1982. 
Two pair currently.  

Oh yes MC, Joe Weber at Corner Audio. Spent lots of money there, Joe got me into high end audio.

Anything with copper....

Quartz....

Shungite....

:)

My dac Starting Point systems is irreplaceable soundwise and moneywise....I hope to own it till my death...

My Macs, C20, MC240, I've had a few. This pair though, they were made for each other Though I'm REALLY liking  the Cary V12r, I've been tinkin' with over the last year. This is out of 45-50 different power amps, and preamps

The speaker, I currently own. VMPS RMx Elixir. and a few that I've made
and kept , and or still working on..So there is 10-12 pairs, 3 pairs unfinished, CLOSE though...COLUMNS.... Everything else GOES.

I keep a cool 1/2 dozen to a dozen  Russco, QRKs, or Spartas, for TT project every now and then.. Garrards are too expensive. I like Thorens too 124...a little more reasonable.. FUN stuff. easy to work on, and sound good.

I lost a Fairchild 750 all dolled up.. I was pretty sore about that one.. I would have never sold it... Was stolen... I still cant figure how they loaded it up. 250 lbs..

Regards

Teac X-7R reel to reel.  I no longer have it....if it would’ve been a car, it would’ve had 500,000 miles on it when it gave up the ghost.  Absolutely loved that machine, but it definitely belonged to another era, IMO.  I wouldn’t seek out another one now...

My von Schweikert db99 loudspeakers 

Favorite? Probably would have to be the Linaeum Model 10 speakers bought at Corner Audio in Portland back in the 90's. Linaeum was a small company making speakers with an interesting driver that was basically a normal dynamic driver that instead of the voice coil driving the usual cone they removed the cone and replaced it with a plastic ribbon.  

It looked like what they did was glue a straight brace right across the center of the voice coil and attach two ribbons to it. These curved out kind of like a horn, only they kept curving around all the way back 180 degrees, and they were very flexible. The idea being the wave form travels or ripples along the ribbon for very low moving mass. The Model 10 used two of these back to back, a dipole in other words.

Whatever the story the sound was the sexiest most luxurious 3D sound stage presentation, probably that I have ever heard. I mean, an audiophile friend who was no fan of my system nevertheless said you weren't listening to a soundstage, "you're swimming in it."

They had problems. Voice coil heat could melt the ribbon if played too loud for too long. But the real problem was they had a real prominent bass hump. Sins of commission really are worse than sins of omission. Yet its my favorite? Maybe because another saying is also true: Absence makes the heart grow fonder. 

Best? That's a close call. Synergistic Research Atmosphere Level III Euphoria interconnect. Hard to believe an interconnect can be so good. But I would probably have to give the nod to my Tekton Moab speakers. Transformative, they are.

Things you would replace without considering alternates?

You make me realize I have several things I won’t change unless they die. Keep in mind, I’m 72, so over many years you get to keepers.

As I said, I will never change or part with my speakers (custom enclosure/vintage drivers from 1958). I have a full set of spare drivers downstairs, and just checked yesterday, the vintage cloth surround re-cone kits are still available for the 15" woofers.

I also said I will never part with my Vintage McIntosh mx110z Tube Tuner/Preamp. I just wrote this AM, to Audio Classics asking them what they might charge to ’upgrade/overhaul’ them (just to know). If trouble presents itself, I’ll drive up there, 5 hours away, drop it off, visit my friend who lives near there. Dead, I would buy another without ever considering an alternate.

My TT, just added a 3rd tonearm to Vintage JVC Plinth CL-P2, I will never change that plinth. Spinner, TT81, never change it unless it dies, then direct replacements are available. 3 Arms, no desire to change, but if any arm dies, I would search, consider alternates.

SUT, new to me Vintage Fidelity Research FRT-4, if it died I would get another one just like it. It's 3 inputs match my 3 arms, and 4 optional loads give flexibility for future MC cartridges.

Reel to Reel, Teac X2000R, I have 2 active and 1 spare, their last ’Prosumer’ model, never consider another, I know all about their innards.

Office TT, vintage Vertical on top of BC. Only vertical will fit. Mitsubishi LT-5V is so cool looking, and a high quality linear tracking, I’d get another if it died. I’ve got some spare parts downstairs, but mice ate the electronics, so only physical replacement parts are good. They made similar taller units ’Interplay’ with vertical Tt and cassette and fm and aux input. If this died, just for fun I might go for one of them.

I frequently mention Chase RLC-1 Remote Line Controller for remote volume and remote balance. I will never live without two, 1 main, 1 office, and I have a 3rd on the shelf.

Oh yeah, my 8 Track Player. POC, but I designed the offices of Columbia House, and it was a gift.

I will never change or part with my speakers, but I do change components infrequently.

Now, the next thing I will never part with is my Vintage McIntosh mx110z Tube Tuner/Preamp.

If trouble presents itself, It will be overhauled by Audio Classics pronto.
Dead, I would buy another without ever considering an alternate.

I'd say my old favorite was when I got the NAD 2020 integrated amplifier about 45 years ago. I wish I still had it but changed to an Adcom 5400 amp about ten years later. Current favorite piece is Watkins Generation 4 speakers (prototypes labeled "custom design" with Bill Watkins name underneath). Before those speakers, I had Watkins WE-2, a smaller version of the massive early 80's WE-1. I was also quite fond of my old Grace F-9E mm cartridge which was used with the NAD years ago.