Toughest Division in Pro Sports?

The last 3 years the NBA SW Division has led the NBA with regular season winning percentages of 55%, 55%, and 61%. The NFC West posted winning percentages of 47%, 56%, and 66% over that same span.
This year 80% of the teams in the NBA SW Division are in the playoffs.
NBA teams play 10% of games within their division, while NFL teams play 37.5%. Which Division is tougher, and are there any other major sports who have tougher divisions than these? Does Monty deserve some slack for being stuck in such an excellent division?