Honorable mention to the remarkable Stan Musial, who in 1948 missed achieving this feat by 1 HR. That season he led the NL in runs, hits, doubles, triples, RBI, BA, OBP, SLG, OPS (duh) and total bases. I don't know if it's the greatest offensive season a player ever had (tough to top Ruth in 1920, 1921, 1923) but it is certainly unparalleled in MLB history.