Clear conclusions or Anonymous Ending?

Which is better? Do we like to read stories that have a clear conclusion and leave nothing to the imagination? Or is it more preferable to allow ourselves as the reader to infer how it could turn from it's end? Should the story close with the hero standing victorious, or with him charging forward into the face of death itself? Each one can have it's own benefits and disadvantages. But which is better? Certainly, it might seem pleasurable to have the story end with something already thought out and written. But do we not enjoy it if it ends with a hint of mystery as well? State your thoughts, noble readers.