All sports have traditions that help make them what they are. Hockey is no exception.
Start with the fact that the game is played on ice and originated in Canada, and you have two reasons for many of the traditions in the NHL today.
Here's my list of the 25 best traditions in hockey. Keep in mind these all apply to the NHL, although they could apply to other leagues and levels of hockey as well.
Some will be specific to one arena or team, but most will apply to the game itself.
Feel free to comment on these or add any I may have missed.