..three actors. One is worst at remembering his lines, another is worst at speaking clearly while the third is worst at understanding the character...You can't compare apples and oranges and have a valid comparison. If one actor is worst in one dimension and the others are deficient in other ways, which you should choose depends on your relative weighting of the parameters.
Going back to the original query: when all three choices are bad, one takes the
least bad, acknowleging it perhaps to be the best of a sorry lot. "Least worst" could be given in mock innocence: humorous and childlike language used to emphasize a point with cuteness. But not grammatically accurate, as Bill was the first to point out.
Edit: Guess I should have read to the end of the thread before replying ! My points have already been expressed.
