at its best

at best

1. In the best possible scenario. At best, Doug will be only an hour late. They're only selling junk at the yard sale, so I think they'll make $10 at best.
2. Ideally suited for success. In this usage, a pronoun is used between "at" and "best." I'm not at my best when I'm tired.

at its best

Of or at the highest standard of quality possible. You'll love their new album; it's simply jazz at its best.
Farlex Dictionary of Idioms.
See also:
  • at best/worst
  • at one's best
  • best-case scenario
  • scenario
  • look (one's)/its best
  • look your/its best
  • as best (one) can
  • as best one can
  • as best you can
  • (had) best (do something)
References in periodicals archive
Black corn truffle tamales, lobster enchiladas blanketed with pumpkinseed sauce, pickled ancho chiles stuffed with foie gras...This is hybrid cuisine at its best. Presidente Masaryk 513, Colonia Polanco.
Mexico City. (Best of Latin America)