I'm not sure how many Linux users are on this forum but from what I've seen, nothing compares to the output of LilyPond. Perhaps it's not the easiest to use, but coupled with Denemo, once you get to know your way around your productivity can rival that of any program, I believe. I am fairly certain there is a Macintosh port and I would guess there is also a Windows port, but I can not be certain.
And Denemo, a graphical frontend which works well. There may be better GUIs in existance, and if anyone knows of a good one I would appreciate to know. I hear NoteEdit is alright but have not yet tried it. Thank you.
A little propaganda about LilyPond: While going through this much "work" just to make a score look nice (and that's a subjective word to begin with) may seem superfluous, I sincerely think it is worth the effort. Once you get past the initial phase, you quickly realize it is actually a much quicker and smarter way of writing music. With that said, I hope someone here decides to at least give it a try. Also, I am in no way associated with LilyPond, I just like it a lot. Thank you.