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

My all time favourite piece of kit is my Michell Gyrodec bought in 1992 (for £659 !!!) and subsequently upgraded to Orbe status. Now with SME V tonearm and Koetsu Black cartridge and still in regular use to-day. I have had other turntables down the years and wish I had had the funds to keep them rather than having to trade them in !! (Pioneer PL12D, Thorens 160 Super, and Dunlop Systemdek III, the latter equipped with an outboard power supply which made all the difference).

Tice clock. Vpi magic brick. 
Seriously, As  smandlej above, Michell Gyrodec Full Plinth, SME V arm, remove the bridge, full Gert Pedersen mod takes it to another level. 

Original Audio Research D-150.

Wish I still had it!

Cheers!

I don't think I will ever part with my Emotive Audio Epifania preamp and Vita amps. I have owned them for over 15 years now (serial #2). Over the years some changes have been made. The original caps have been replaced with VH Audio copper teflon caps (preamp and amps). The preamp's original volume control was replaced with an autoformer volume control, and the plate voltage on the amps was increased to properly run 6550 tubes (originally used 6L6 tubes).
I've changed speakers a few times and am currently using Bache Audio Tribeca's.