Mississippi Queens.
Warmer, fatter and more articulate on the bass strings than the Stormy Mondays ( the 'usual' choice ) .
More so ( on all counts ) than the Alnico II or Alnico IV Stormy Mondays, which are very clean sounding, but play with less warmth and authority than the M.Q. in a Jazz guitar. The powerful and yet balanced nature of the M.Q. sounds better than Stormys or Mules at lower volumes too. If playing solo, comping, or playing in an intimate setting - they dominate the amp and stay tight without losing warmth. with the pickups on my 335 copy set about 1/16" from the strings ( 1.6mm ) give or take half a turn or so of the pickup screws, I would even say they sound slightly compressed, which keeps it all tight whilst remaining sweet.
See also the other thread currently running on a suitable 'Jazz' pickup, where Jonathan from 'Feline Guitars' also comments on the use of M.Qs for such purposes. :)