Fender J bass. It would be hard to find a place on this planet where more than 10 people lived that you couldn't find pretty much whatever you needed to keep one up and working.
It's pretty much the same for the P bass though. I prefer the J and always thought it was the slab of a neck that put me off the P bass until I took a few days to A/B my J against a P bass special that came from Fender with a j neck on it. That was when I discovered that a P hangs with the neck parallel to the deck while a J hangs with the neck at a slight upward angle. Nothing against the P, just one of those old dog new tricks situations.
"Strictly speaking, there is no certainty, there are only people who are certain." -anon-