I've played around with several styles of endings for plots. Cliffhangers keep the reader wanting more, but then you have to deliver.

If you don't deliver, that leads to disappointment. Disappointment leads to anger. Anger leads to the Dark Side. Alderaan would appreciate it greatly if you didn't send people to the dark side.

Sunset fadeouts, with everything resolved, can be satisfying, but tend to come off as cliched. A mix of the two styles seems to be considered standard lately. Everything ends well, but wait, the last scene flashes some plot twist justifying a sequel.

Even with that scenario, you'll still run into the same dangers of having to deliver on the whole "Make it as good as the first one, then make it better." I've tried to experiment with a slight alteration to this method. Initiate a ledgehanger at the end of particular chapters or sub-plot arcs. The sunset fadeout can happen later, but in the meantime, I'm going to end a chapter with my main hero just missing the much needed escape from the exploding laboratory before things go aspodey kaboom.

Sure, he'll come out alive in the next chapter...more or less, but the reader won't know that. Unless they start reading the following chapter. Mwuahaha! *twirls my evil mustache that I don't really have but would grow for such occasions*

The nice thing about using this in short stories is that ledgehangers can be used to build up to the plot's climax, and then I can sunset fadeout through the resolution, while the villain staggers off to his backup lair to lick his wounds.

One thing I would strongly recommend, for those who go the cliffhanger route: know what the resolution is before you make the first part public. Readers will be anticipating the second part of the cliffhanger and won't appreciate or understand if you flub it up due to lack of planning and foresight. If your character literally falls off a ledge, you better know if there's a branch, ledge, or bouncy house to break your character's fall. Or, if there's nothing to break the fall, know what the consequences of that character's presumed demise will be to the rest of the plot.

The readers will want to know, and not offering up some sort of explanation will break the flow of the plot and annoy the reader (or at least readers like me). If Character Q is last seen in with a gun being fired in his direction, I want to find out at some point whether Q was hit, grazed, or, if the bullet was evaded, ricocheted off a nearby pot and hit the shooter instead. Give the reader details, even if it's a couple lines that tie up any loose plot threads. Readers like myself will appreciate it.