Malkin had six goals and 14 assists in 13 games as the Penguins (21-13-4) finished the month fifth in the Eastern Conference and just four points off the conference lead.
The 25-year-old increased his season points total to 43 (15 goals, 28 assists) in 31 games and climbed to sixth in the NHL scoring race.
Stamkos surged to the NHL goal-scoring lead by scoring 10 goals while adding seven assists in 13 games.
The centre helped the Lightning (17-17-3) end the month within six points of the eighth playoff spot in the Eastern Conference.
Sedin led all scorers in December with 22 points (two goals, 20 assists) in 15 games. The Canucks centre vaulted to first place in the NHL scoring race, spurring the Canucks (24-13-2) to top spot in the Northwest Division.
Sedin had points in 13 of 15 games, highlighted by six multiple-point performances.
He begins 2012 with the points lead (10-36-46) in a bid for his second Art Ross Trophy in three seasons.