My Bruno Royal Artist thinline semiacoustic guitar.
Simple because it's the beginning point.
Apart from that I have to admit that I still own 2 Yamaha MT100 4 tracks, a Roland 8 track DiscLab, a Zoom R16 in addition to Cakewalk ProAudio 9.3 and Reaper as well as an INCA 8 I/O w Breakout Box.
I've only old one piece of gear & I instantly regretted it as it becaome, in hindsight, my most important piece of kit.
You wouldn't believe the old, outmoded, lofi mics I can't let go of.
Everything is useful in its own way & can do at least one thing very well indeed.
I had a tech in recently and he marvelled at my Aletc Lansing Electrovoicette Graphic EQ (massive piece of metal) and regaled me with stories about the AL gear used at Woodstock. Would we have gone on to discuss the difference in live recordings fo the Woodstaock era against the 80s and 90s without it? Unlikely.
That sort of interaction is worth keeping a piece of kit for anyday.
Man, I'm a real dag aren't I?