Colored stone? COLOR first.
Diamond? Again... in a modern stone, CUT. In a vintage stone... something else.
Overall though, as long as it's eyeclean and SAFE with regard to inclusions, I'm happy with it. Everything else, it depends on what I am buying. Clarity is generally not ever gonna be high on my scale, unless I'm buying a large step cut.
Cut - I wanted it to be a top performer #1
Color - wanted a warm color, I-J-K
Clarity - I have sharp eyes, had to be VS2 or higher
Carat - Anywhere above .5 was good enough for me