Bostons Don Awrey was the best shot blocker of the mid-to-late 60's through 72 era. Completely selfless.
Never mind the much vaunted Leafs blue-line, Awrey took it to a whole other level. Played mainly with Orr.
After leading the regular season in that stat (in only 75 games, he blocked 34 more shots than the next-closest player) Jay McKee was third in blocked shots in the 05-06 Playoffs. The first and second guys in this stat, Jason Smith and Chris Pronger, had another seven games worth of time each, and only blocked three and two more shots respectively.
It's a damn shame he got that staff infection before game 7, and his contributions to the Buffalo blueline during that run are criminally underrated outside of upstate New York. It doesn't help that the Blues overpaid him by a ton the next year, but still, guy was a beast.