Marián Hossa
After the 2007-2008 season when his team, the Pittsburgh Penguins, lost to the Detroit Red Wings in the Stanley Cup he switched teams to the Detroit Red Wings because he felt he had a better chance of winning the Stanley Cup with them.  When the Penguins again met the Red Wings in the Stanley Cup after the 2008-2009 season, Hossa was once again on the losing team as the Penguins won in 7 games.