Given the fact that PIT finished where they did in the east, despite starting the season without their top 2-way forward, and finishing without their top-2 forwards (and 2 of the 5 best forwards in the NHL today), I give it to Bylsma.
But Trotz is a perennial favourite too. AV is worthy too given the decimation of the VAN defense this season.
All are worthy, but not quite as much as Bylsma. He had to turn an offensive team into a defensive one at the half way mark! I think he runs away with this.....