Probably the most well known to an America audience is the Irish Wake. The traditional party that was given in Ireland to honour the dead and to mark their departure to the next world. To the Celts, same as in Christianity, death was only the fading of the physical form. It did not mean the end of the spirit, the essence of the person, more that they returned to where they came from. Quiet zen in fact.
The wake a way of acknowledging this. It is also a positive way of dealing with grief, as neighbours and family chipped in together, to feed everyone, and to organize the event. It was a way of the community showing how they were there for the family of the deceased.
In other countries burial traditons vary depending on what the religious belief of the area was. In Tibet, a buddiest country the body is fed to vultures. In a land with little soil, it made sense and it ties in with the concept of Buddhism that we are all one, whether that be God or nature. It was the cycle of life. One nurtures the other and then moves on to the next cycle of existence.
Burial traditions are important in that they give structure to a difficult time.