amilli wrote:I realize that the majority would rather have a "deus ex machina" or a more traditional ending when reading a book or even watching a movie (Not necessarily a predictable ending, but one that is neatly tied together). If the villain got away, the MC's goal was not achieved, or the super hero dies, then there's a sense of disappointment. An "Awe man, I wish there was a better ending" kind of response. I'm guilty at times
Well, before I get to the very excellent question in your second paragraph, I need to address something here. A
deus ex machina ending is BAD, but not every "neatly tied together" ending is bad, nor does it necessarily contain a
deus ex machina. If the ending is neatly tied together by the improbable and sudden intervention of someone or something that only appears for the purpose of tying things together--that's what we're trying to avoid. But neatly tying things together is FINE. In fact, one of the best YA books I've ever read--
Holes, by Louis Sachar--does a spectacular job of tying multiple threads together by the end of a book with numerous plots and subplots across several different settings of time and place. If you haven't read it, I heartily recommend it.
amilli wrote:But my question is: What should be the aim of a good ending? I know that good stories have conflicts, but like yours and so many others, the conflict does not have to be resolve at the end. So what should a good ending do for the story it's concluding? What is the purpose or what should the ending accomplish? (Hope my question is clear

)
The ending of a story (whether it's a micro-fiction story as in the Writing Challenge, or a full-length novel)
should leave the reader satisfied. That may sound like a cop-out, but I can't think of a better way to say it. The thing is, there's no one way to satisfy the reader.
An open ending may be perfectly satisfying, if the the reader feels as if she "knows" what's going to happen next. Conversely, some readers despise an open ending; they want to know how every strand is tucked into the final tapestry.
So--is the key to write a tidy ending, with every conflict fully resolved? Maybe. Particularly in some genres (romance, mystery), that's the desired outcome. But that's also the easiest way to fall into the temptation to write a "magic" ending. And some genres (contemporary literary fiction, for one) are often better without complete resolution.
A happy ending, then--surely that's the best, most satisfying way to end the narrative, whatever the genre. Well, not necessarily. There are times when a happy ending isn't realistic or satisfying, and a tragic ending is the only thing that will work.
This may be frustrating you, if you wanted a pat answer. The only thing that all of those possible types of endings has in common is
the writer's craft. A good writer will make any kind of ending satisfying; a poor writer may not.