I like endings that wrap things up, both as a reader and a writer. I don't like to be left hanging, and I don't usually leave readers hanging with my endings, unless it's to lead into a sequel.
As far as happy vs. sad, as a reader I prefer sad stories with happy endings, but as a writer, I like them bittersweet. My favorite kind of ending to write is one that will make people cry, then smile through their tears. I don't mind that kind of ending as a reader, either.