When and what was your last significant equipment upgrade?

Vandersteen 4A to Wilson Maxx 2s.

Emotiva XPA-1 GEN 2 Monoblocks
Modwright LS36.5 DM Tube Preamplifier
EAT Forte Turntable w/ Moerch Tonearm & ZYX Universe Premium Edition cartridge.

Adcom GFP 715 to Rogue Metis Magnum and Rega Elys 2 to Exact 2 for my RP3

Building and listening to my set of 4 Walsh speakers.  Next upgrade is the new and improved version of the same, in the same quantity.
Unlike the original Ohm's, they're a '2 way' with a smaller unit above the lower and larger driver.  The larger driver is slightly larger than the unit one sees applied in the German Physiks offerings, which is what I'm patterning them after.  And I can bi-amp them with a digital xover....
They're not perfect, but I listen to them far more than I do to my more 'normal' speaker array.  I've not noticed any 'listener fatigue either, which I can only experience elsewhere with my AMT's.

The newest addition for me is different speaker cables.   I've spent years with oh so many brands....high priced, low priced, and everything in between.... the ones I have now just work.  Ease, extension, clarity, etc.  Don't give up your search until perfection is found.