Which nail polish brand should I use to finish my collection ??

Yves Rocher! Its one of my favorite brands. Its really good and quite cheap.

Too late, since you already picked a best answer, but please try Zoya. It costs about the same as OPI or Essie, but it's so much better.

Coverage in one coat on some colors. You can cut and file your nails without it chipping, at least sometimes. I stopped buying any other brand a few years ago.