Now, I don't think every ending needs to wrap up perfectly, or with a typical "happy ending." The ending of Where Gods and Mortals Dance doesn't offer an actual resolution, but rather it provides the characters with the means by which to fix their problem. I leave what happens in the minds of the readers, which I feel both shows a great amount of trust in the imagination of my audience, as well as the idea that, like real life, many issues are ones that require years to finally accomplish, if they are accomplished at all. The conflict in WGMD was such that it wasn't possible for it to be completely fixed at the end without feeling like a cop-out, a "happy for the sake of being a happy ending" ending. I think these endings, above all, are my favorite to write, though they might actually not be my favorite to read.
Beginning with the end in mind is also a fantastic motivation. Knowing I have something fantastic and mind-blowing to present is an excellent motivator, one that can help push me through slow or boring portions, knowing the payoff (for both me and my readers) will be well-worth it. It also give me a basic framework which I can build my story; because I have an ending, I know what needs to be foreshadowed and implied. This also makes the foreshadowing, something I admit to have problems with, an easier task to accomplish.
Just a random musing concerning work in Paradise Seekers. As we are a little bit into the second act, with the third one right around the corner, I'm finding it important to keep the point of the story in mind. The truth behind the Paradise Seekers, their dreams, Dissipation, and more is integral on both the hints leading to the ending and for readers to find the ultimate underlying meaning behind the book. The point of Paradise Seekers is to both tell an interesting story in a unique environment, and for those who wish to dig a little deeper, they'll find the hidden symbolism and analogies throughout. As I am now in the point where I have to put the right amount of hints and foreshadowing, if I didn't know what the overall point of the book was, I wouldn't be able to accomplish it.
All in all, beginning with the end in mind has been very helpful for me in all my books, and it is something I'm going to probably do throughout my writing career. If I start with the point of the novel, producing it is much easier, and (I feel) makes for a better ending (if I have it fresh on my mind throughout the entire writing process, I have that long to refine and perfect it).