just like the title says, I think there should be a Pin to Top response on threads, you know, most of the times stupid people post an out off topic response first, after the 2nd or 3rd response there is a decent response and about the 8th or more there is a response that is exactly what you are looking for, anyways the Pin to the Top response/comment/reply is not such a bad idea, so that the person that created the thread can have his/hers favorite response at the top..
its a suggestion only and I know what you administrators are going to say..
"THEY ARE GOING TO ABUSE IT" if that is your response dont reply, and ignore this thread..