Honestly, I love endings where I'm left wanting more of that world. I'd rather get a satisfying ending that leaves me chomping for more content I can't have, than to have so much content that I just burn out on it or, a situation where they screw up an ending and make it feel like a waste of time.
The highest accomplishment for any media for me is leaving me wanting more of that thing.
RE: I Completed Mass Effect 3 Yesterday