At best or At the very best. Looking at the matter in the most favourable light. Making every allowance.
“Life at best is but a mingled yarn.”
At one's best. At the highest or best point attainable by the person referred to. For the best. With the best of motives; with the view of obtaining the best results. I must make the best of my way home. It is getting late and I must use my utmost diligence to get home as soon as possible.
To have the best of it, or, To have the best of the bargain. To have the advantage or best of a transaction. To make the best of the matter. To submit to ill-luck with the best grace in your power. Source: Dictionary of Phrase and Fable, E. Cobham Brewer, 1894