No prizes for guessing here. My 1990 MiJ 60s reissue jazz bass. Ive owned it since around '92 and used it for thousands of gigs. The only original part these days are the body and three of the tuners. The rest is a wonky hodgepodge mishmash of parts. For a time it had an East preamp, EMG pickups and Status graphite neck and an 'Animal' sticker. The original neck was sold on here when it was bassworld.
These days it has an allparts neck, badass ii bridge from about 1993, a custom 'signature' split Humbucker in single-coil sized casing. (Its a Wizard 'GAFfer') in a cream casing. The bridge has a Seymour Duncan quarter pounder in there. These are all hooked up to some fancy pots with some fancy wire and squished into a brass shielding doo-dah thingy similar to the one that got pulled out decades ago when the EMGs went in. Since the 90s its also had a vintage style hipshot de-tuner that goes the opposite way to all the others!
The paint has been randomly splitting and chipping for years - add that to the gig wear and its looking pretty tired, but it sure has some stories to tell!
If things had gone differently, this would definitely be the one I'd be asking Fender to make a signature. I've owned over 300 basses now and this will always be the one that's the most 'me'.