I've no idea if I've found the 'one'.
For my playing style (more so if its all fingers and no pick) the simple Musicman Stingray nails it. Perfect weight, neck dimensions, feel, and the pickup placement feels good to rest on. The tone is also, in my opinion, one of the three 'core' tones. You have classic Fender P, Classic Fender J, then the Stingray which, in all honesty, has such a brutal yet tameable tone its unreal. It WILL do old thump/almost upright, it will then also snarl in the mix and provide effortless tight E (or B ) open strings that have really made me realise just recently why I like it.
The P is my original 'home' instrument, and the J I own purely because I like the tone and the style, but the neck dimensions are sometimes not right for me (although I still like them).
The other point is that no other humbucker sounds like a Musicman. Dingwall, Warwick, Lakland, Sadowsky, Nordstrand pups; none of them sound like a real Musicman pup,
I think in addition, since I was around 12/13, the Stingray was the first bass I REALLY took a shine to, (but i had to stick to my Encore P bass and a Tanglewood Ray copy for a while). I think my tutor basically said 'everyone needs a Stingray', and so that was that!