Yes, I was waiting to see if someone mentioned him. It's Boivin, though. Several times I saw him check a player and that player went sailing through the air, sometimes head over heels, and not in the direction the checked player was skating, indicating it was the force of the check and not momentum that sent the player flying. He was not tall, but short and squat, built like a bulldozer and he could deliver the most crushing checks. He would check them low, and that's why they went flying. As he grew older, he slowed down a great deal and the checks like this came few and far between I did see one, however, in the mid-Sixties that was as good as any of those he delivered in the Fifties when he was a youngster.
For me its definitely Lindros. He grinded guys down. If you got in his black book you where in for a ride. I mostly think of Stevens when hits to the head are mentioned. But they certainly were hard, retirement hard.
Larry Robinson closed on opposing forwards better than any defenseman I have ever seen. He would give them a little opening to make them think they could skate by him along the boards, and the moment they took the bait, he closed the opening and quite often, ended their night. Not only was he absolutely huge, his tremendous speed added to the force of the impact. It's rare you see such a mix of size and skating ability in a defenseman today, and it's even less likely to find one that plays a physical style of game.
Scott Stevens lost a lot of mobility as he got older, and he was more of a North-South hitter who took advantage of forwards who weren't paying attention. Robinson got forwards to pay too much attention to the open space he left for them, and his skating gave him the chance to take away that space in a matter of seconds.
Scott Stevens made up for slowing down with smarts. The guy had amazing hockey sense. He knew exactly where the puck was going to go before almost anyone else. And he got there just as the forward on the other team did, at exactly the right time to level him.