The Vancouver Canucks seem to be the best place for Mats these days.
One of the front runners in the Sundin race, Vancouver would benefit large landing a player like Mats.
Needing a good replacement for Trevor Linden, Mats is arguably a better player and a lot better to fit in a roster with four other Swedes. Alongside of the Sedin brothers, Mats could help the Canucks' top line dominate in the league, if he decided he wants less responsibility and is willing to drop to right winger.
Mats playing alongside of the Sedins would allow Mats to slow his way back into shape, not having to take such a huge role immediately. The line could really mess up the opposition using their native tongue. Adding the two Swedish defensemen could possibly make up a monster power play.
Another reason Mats would fit in Vancouver well is even if he takes the number-two center role, Mats could mesh with fellow former Leaf Kyle Wellwood, whom he was already previously linemates with.
Sundin in Vancouver seem to be the best option overall. Not only does Vancouver have the cap space for Mats, but they have the goaltending needed to win Cups—and that is exactly what Mats wants to do to seal his legacy in NHL history.