Let's see, I have quite a few
Seymour Duncan SPB3 pick-ups - These gave me a much better sound when I put them in my old Squier P-Bass, after I put them in my confidence skyrocketed becuase I sounded worlds better than I did with the stock Squier pick-ups
Hennessey strap-locks/With an Ernie Ball Strap - I have long arms and I prefer to play lower, so the Ernie Ball strap helped me lower my bass to a comfortable playing level, which improved my right hand/wrist/elbow/shoulder movement (I use a pick, so I use my entire arm to hit the string). The strap locks just helped me avoid the annoying situation where a stap comes off/is about to come off while playing and you either have to stop what youre doing and fix it or hope that it doesnt fall at all
Ernie Ball Power Slinky strings - After bouncing around several different kinds of EB strings, these really gave me the sound and playability I've been looking for for a while
Fender Kingman EAB - This wsa perfect for me, it had the Fender neck and felt very comfortable in my hands, it was perfect for playing when you cant plug into an amp yet want to hear what youre playing, and with the high action it helped strangthen my fingers and forearms so when i went to play my p-bass, scaling and moving around the fretboard was significantly easier. Also, it helped me with my finger-playing, learning how to play with my fingers came much easier on the Kingman that it did on my p-basses. All-in-all, it was probably one of my best investments as a musician, I play it almost everyday. Plus, with the built-in tuner, my pitch recognition became such better, now I don't even need a tuner that much anymore because I can hear where I need to be.
that's about it for equipment, at least the things I can think of off the top of my head
