Is there one item you have been wishing for?

I understand you asked about one component not the entire system.
Having one state of the art piece and junk by comparizon for the rest?
Well, I'll cheat a little. I would choose the best room I could find.
And without cheating, well, maybe LAMM reference amp.
That Swiss stuff would sound like junk by comparizon, by the way.

The perfect Room for what I have now.

Pay off my mortgage so I can spend a bit more freely on audio.

Elizabeth, let me help you approach your dream system.
Sell all the garbage that you have now. I mean all of it. It is garbage by your standards.
Then get used MBL speakers, used MBL integrated amp with phono, used Nottingham Spacedeck/Spacedeck table with new Dynavector MC or Garrott MM, and used CEC belt drive or Meridian cd player. Purist Audio and DiMarzio cables, some power cords.
If needed, sell some of the LPs and CDs which are not very valuable.
Then you'll have a sound.
But since for most people dreaming is better than having, you'll never do it.

In athletics, there is a saying "you're only as good as your next race." The equivalent here is that the item I'm wishing for is always the next one after my most recent upgrade. Over the past 3 years or so I've upgraded the amp, pre-amp, phono stage, and speakers. So now my daydreaming turns to upgrading my turntable, an original early Linn LP12. So I've been looking at the MOSE power supply, possibly the Sole undercarriage, or just upgrading the cartridge. Or going to a different TT altogether, There's always the next thing to wish for...