I haven't tried every value but Eric Johnson mentioned in the Fender Virginia Strat interview that he preferred pots somewhere around 400k so I soldered a 2.2M resistor in parallel with a 500k pot (~405k total) and liked it. Then for some reason I tried a 280k pot and the 400k went right back in, definitely preferred it. But the tone pots are still 250k or even a little less, like 235k-245k.
I've been using those pricey square blue Bourns pots but recently got some PRS, Duncan, and Vintage Inspired Pickups (the 280k) pots to try. I like em loose and the PRS feel really great but that guitar isn't done yet.