best \best\, n.
   utmost; highest endeavor or state; most nearly perfect thing,
   or being, or action; as, to do one's best; to the best of our
   ability.
   1913 webster

   at best, in the utmost degree or extent applicable to the
      case; under the most favorable circumstances; as, life is
      at best very short.

   for best, finally. obs. "those constitutions . . . are
      now established for best, and not to be mended." --milton.

   to get the best of, to gain an advantage over, whether
      fairly or unfairly.

   to make the best of.
   a to improve to the utmost; to use or dispose of to the
       greatest advantage. "let there be freedom to carry their
       commodities where they can make the best of them."
       --bacon.
   b to reduce to the least possible inconvenience; as, to
       make the best of ill fortune or a bad bargain.
       1913 webster
see also:
at best for best to get the best of to make the best of 

at best
     adv : under the best of conditions; "at best we'll lose only the
           money" syn: at the best ant: at worst
see also:
at the best at worst