Fountain of Knowledge

I need assitance! I need everyone's opinion on this, if you have thoughts, feel free to weigh in. I have a brilliant, stunning, gut wrenchingly emotional new story idea. I've been trying to think of something to write about angels, and with a little bit of unintentional inspiration from other people around the site (MetaphorSquared and Reyah - go read their ports, they rock), I've finally come up with a basic foundation for my 'angel' story.

Here's the problem - I dont' know how to end it. I have a few possibilities in mind, because really, there's only so many ways you can end a story. So what I want to know is, on a general, basic level, what kind of ending does everyone here prefer:

Everyone lives happily ever after
A good number of people die, and the world is better off that way
Ambiguity - the author implies what may happen as the story continues after the last written word, but never comes out and tells you.
Something I didn't think to list here.

I tend to lean toward the ambigous ending a lot of times, as personal preference, but I'm just torn. So...what does everyone else think?