I write for me first, and then the audience, but I must admit I tend to write bittersweat ending. I mean I have a few Stories That end in "HEA", but the majority are bittersweet. I mainly write fantasy, sci-fy, and horror, but all my stories have a touch of horror in them. I don't know why, It just happens. But I have nothing against "HEA" ending and some of the best stories I ever read end Happy Ever After.
Thank You