The longest you have owned any gear?

I had a Quad 405 amp that I 8 years later had the Mod Squad do their mod to it for 27 years of continual use.  A Kenwood KD-500 TT w/ Grace 707 arm for 21 years until the TT started having troubles keeping the correct speed.  Had Von Schweikert's original Vortex Screens for 18 years and sold them to someone that still uses them 9 years later.  I still use a Harmon-Kardon TD-120 cassette deck in my prime system a little and it has been 23 years.  The heavily modded Lenco 78 TT I have dates back to 1970 (47 years old) says the dude I bought it from although I've only had it for 5 years.  The stuff I now own is because of a plan many years ago and it is pretty much finished.  Will have 2 of the components modded with upgraded parts by a couple of different fellows with much experience at each component--won't change the house sound, but will make them both more reliable and much better sounding.   It's about 50/50 as to which thing was more important--the reliability or the sound.  I loved what I have but the reliability is very important to me as one of the component's designer is no longer alive.

I realize the last 1/2 of my post goes off the OP's premise, but I see this as a check of your satisfaction level along with the battle against the desire to acquire.  Bottom line is I love my system and the music it produces.

I have a Cecil E. Watts Record Preener rattling around in a box. Before the introduction of the Discwasher in the early 70's, it was THE record brush.

I'm one of the more unusual folks here, I guess.  Don't change stuff all that frequently and have kept all the stuff I really liked.  All of my "vintage" gear is at least 28 years old.  Only bought one piece used and the Sansui was a hand-me-down from my parents in 1976.

Purchase date, oldest to newest:

1970 Sansui 1000x receiver (AM section out, bedroom system)
1972 Stanton Parastat Mk. IIA brush (retired now but still pretty)
1975 Discwasher brush (still in use)
1980 Discwasher brush (still in use)
1981 Tandberg TCD440A cassette deck (in primary system)
1983 RGR Model 4-1 preamp (just recapped)
1983 Rogers Studio 1 speakers (primary system mains)
1984 Sota Sapphire turntable (in primary system MC)
1986 Belles Model 1 power amp (in 5.1 subsystem for surrounds)
1989 Pioneer PL-15 DII turntable (bought used, in primary system MM)

Still have 2 original pressing LPs I played through that old Sansui when my folks would let me back when, too:  Cat Stevens, Teaser and the Firecat and Simon & Garfunkel, Bridge Over Troubled Water.  They're even still playable, to a point.

Much happy listening here.

McIntosh C26 and Crown DC 300A purchased in 1974, still in use in my office system. At the time, I couldn't afford the extra $100 or so for the matching McIntosh 2105, so I got the Crown.