The word best is an adjective, and adjectives do not take articles by themselves Because the noun car is modified by the superlative adjective best, and because this makes the noun car definite in this context, we use the It is best not to do something Here, we have the adjective best, but this adjective is attached to no noun. Which one is the best is obviously a question format, so it makes sense that which one the best is should be the correct form This is very good instinct, and you could even argue that the grammar is good, but at best it's unnatural.
In the following sentence, however, best is an adjective What was best? if we insert the word the, we get a noun phrase, the best You could certainly declare that after comparing a number of things, you found that a particular one of those things was the best That is to say, it was better than any of the others. Dictionaries state that at best is an idiom But, what is the grammatical function of at best (for example, in the below sentences?) their response to the proposal was, at best, cool
it was the best ever means either it was the best up to that point in time, and a better one may have happened since then, or it includes up to the present. 1 your example already shows how to use best as an adverb It is also a superlative, like greatest, or highest, so just as you would use it as an adjective to show that something is the ultimate example of it's kind when used as an adverb you do so to indicate that the adjective it precedes is to the highest degree possible. Do all these sentences sound good Make the best of your time Make the best of everything you have
3.make the best of this opportunity. It's best that he bought it yesterday Or it's good that he bought it yesterday 2a has a quite different meaning, implying that what is being approved of is not that the purchase be made, but that he is the one to make it 3 it's best (if) he (not) buy it tomorrow. is not a subjunctive form, and some options do not work well. Have someone's best interest (s) at heart to make decisions based on someone's best interests
And from oxford dictionaries, it seems that interests is generally more common In the interests (or interest) of something 2 for the benefit of:
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