It's a two horse race between Roger Conner (Ball Four) and Jason Giambi (Green Sox). As of this writing, Connor has the lead thanks to his 90 point lead in batting average.
The National League race is wide open, with no ideal candidate identified at this moment. The best all-around player is Willie McCovey (Handbasket) but he's been mired in a platoon most of the year, limiting his value. Johnny Mize has the next highest OPS and is second in the league in home runs, but his OBP of .286 is incredibly poor.
That leaves the next tier of all round players with full playing time to get into the mix as well. Does Norm Cash's (Snowhole) playing time make up for Phil Cavarretta's (Pandas) higher OPS?