Eric Lippert's challenge “comma-quibbling”, best answer?

Question

I wanted to bring this challenge to the attention of the stackoverflow community. The original problem and answers are here. BTW, if you did not follow it before, you should

Answer 1

return String.Concat(
    "{",
    input.Length > 2 ?
        String.Concat(
            String.Join(", ", input.Take(input.Length - 1)),
            " and ",
            input.Last()) :
    String.Join(" and ", input),
    "}");