There are various synonyms for the phrase "for the best", which means the most favorable outcome or decision. One of the closest synonyms is "for the greater good" which indicates that a choice is made with the intention of benefiting everyone, even if some individuals are affected negatively. Another synonym is "optimal" which refers to the best or most favorable outcome given the circumstances. "Ideal" is another synonym which refers to the perfect or most desirable situation. Lastly, "advantageous" is a synonym which refers to a situation in which the benefits are greater than the drawbacks, resulting in a positive outcome overall.