A simple notion. Every team in baseball can use an upgrade somewhere, so for your team, in 2013, which free agent do you want to add? It can be realistic if you want it to be, or you can go full out dreaming, like a world where the Yankees add Zack Greinke, or something. I'll stick to realism with my choice for the Indians - Adam LaRoche. The Indians built a tradition of stable and relatively good first baseman starting with Jim Thome and continuing with Ben Broussard and Ryan Garko. Matt LaPorta became the heir apparent to the position after the CC Sabathia trade, and has been a disaster ever since. The Indians all but threw in the towel on LaPorta in 2012, signing Casey Kotchman to a one year deal, presumably part of a series of one year deals meant to tide the Indians over until the arrival of Jesus Aguilar. Aguilar impressed in 2012, but is probably still a year away. Adam LaRoche is a good fit as a guy who could hold first base down until Aguilar is ready. While it will create a roadblock for Aguilar at first, Aguilar can easily become a regular DH. He has no speed to speak of and his fielding is average on his best day, but he has plenty of right handed power. LaRoche will stabilize the position now, leaving it open for Aguilar to take over when he's ready. LaRoche is probably looking at around 3 years/30 million, and while the Nationals will be interested in retaining him, they could easily pass on him, signing Michael Bourn instead, and moving Michael Morse to first.
EDIT: Another great pick would be Nick Swisher, who could play first until Aguilar arrives, and then move back to the outfield.
EDIT: Another great pick would be Nick Swisher, who could play first until Aguilar arrives, and then move back to the outfield.