Toughest assignments in the NHL this season among the top 25 scorers:

This puts some context into some stats, especially +/-. Kopitar and Giroux are great two-way centers, yet they're +1 and 0, respectively. This also makes Tyler Seguin's* +34 all that more impressive.
Summary: Giroux and Kopitar have the most difficult assignments.
Coaches might want to put some better players on the ice against Malkin.
LOL @ the Sedin Sisters.
*Seguin > Kessel