Uniqueness in itself is good.
I doubt, though, that with the millions, or is it BILLIONS?, of photos being taken every day today it is still possible to come up with something unique.
What makes a good photo for me is a clear subject (preferably close-up, or even macro), good light (backlight is something I will always love to see!), no clutter (i.e. an eye for background elements, too), and often the effect a wide open lens can give, i.e. the subject dissolved from its background by blurring that out. (I am not sure "dissolved" is the correct word here :scratch:

).
This was more spoken with nature photos in mind.
When it comes to man-made things (houses, roads, factories, whatever), I like clear lines, vanishing points, repetition, good contrasts, heavy play of light and shadow, geometrical forms.
With people I like candid shots which make them look their best. I love to take people photos with the telephoto lens. (Which also nicely blurs out the backgrounds, back to what I like about photography - for our eyes can NOT blur out backgrounds like that!)