Mine would be Minnesota Boston, back in the days of the Adams division. I believe it started either just as or just before the puck dropped at the start of the game. It set the record for pms at the time.
http://youtube.com/watch?v=tf9XCTUm6MM It was so crazy seeing Mike Bishai fighting the atlanta guy after he had been pulled into the atlanta bench. I've never heard it as loud in Rexall during the regular season.
The Boston Bruins going into the stands at Madison Square Gardens on December 23, 1979.
It is famous for "Mad Mike" Milbury then a Bruins D-man pulling off a Ranger fan's shoe and hitting him over the head with it.
"It's unbelievable that after more than 30 years in the game, pummeling a guy with his loafer will be my legacy. But I guess it's better than having no legacy at all." - Mike Milbury
Have to disagree with Mike there. As much as Islander fans would love his legacy to be beating a Ranger fan with a shoe, the reality is that MM will be remembered for the way he took a franchise with a major dynasty in its storybooks and turned it into nothing less than a travelling carnival. The Isles seem like maybe they're coming out of that period now (good for hockey in the area), but I won't be remembering him for any footwear.
EDIT: And another thing, it's Madison Square Garden. Singular. Just one Garden. Canadians say "Gardens" all the time because they are thinking of Maple Leaf Gardens. MSG came first. It stayed last. Singular. Garden. Thanks for calling.
Here's another vote for the Good Friday Massacre. It was so good they decided to go at it again after the intermission. Also, Philly and Montreal in 1987 after the Flyers grew tired of Claude Lemeiux ritually scoring into an empty net at the end of warm-up.
Wild brawl that went on forever. Bernie Parent's mask got tossed into the crowd and even with the police's help could not be retrieved. Jacques Plante had to replace him because he did not have a spare mask.