For me, it depends on what I’m writing. Publishers tend to want happy-ever-after endings or at least happy-for-now endings. So, if I’m going to submit what I’m writing to a publisher, I try for at least the HFN ending.
When I write for myself, I’m much less inclined to write happy endings. I’m never quite sure life has a happy ending in most cases, although I’m firmly in the camp of life having happy bits throughout. But I think how people cope with adversity that doesn’t resolve neatly is far too interesting not to write it.