1995 Atlanta Braves
1996-97 Philadelphia Flyers
1972 Miami Dolphins
2003-04 Detroit Pistons (not a Pistons Fan, but was a hell of a season for them, and nice to see them crush the lakers)
The '07-'08 Washington Capitals. Started the season 3-0, then was stuck in the cellar for most of the season, pulling off a late season run to win their 4th division championship in team history.