Calendar Module for Drupal

I am looking for the most recommended calendar module for drupal 6. This is for a non-profit that wants to display a master events calendar for the community. Have several users be able to update with events and everyone else just to view.

I have downloaded and tried a few, nothing really seems that good.

Looking for your input.

Thanks so much,

-JP

_{Edit by Michelle: This question has nothing to do with the chat module group it was posted into. Moving to what seems like a more appropriate group.}