Spo took a championship team and made them better. Of course Miami Heat's Erik Spoelstra has the best player in the NBA on his roster, another guy in the top 10 and another in the top 15-20, but he played a part in their success this season as well.
He embraced the philosophy of "positionless" basketball and focused on the offensive strengths of his players. The Heat continue to have one of the league's better defenses as well. Ripping off a 27 game win streak and leading the NBA in wins during the regular season is nothing to overlook either. He may give corny speeches but he's improved as a coach, his team dominated all others and for that he gets my coach of the year vote.
Honorable Mention: George Karl (Denver Nuggets), Mike Woodson (New York Knicks), Tom Thibodeau (Chicago Bulls), Mark Jackson (Golden State Warriors), Kevin McHale (Houston Rockets)