In the end of the Crucible, what is it that is of utmost importance to John Proctor?
When Proctor screams that Salem has taken everything from him, and that the least they can do is allow him to keep his name, there is much present. Proctor's evolution in character is steeped in the idea that an intolerant and inauthentic social order takes people's reputations as its grist. These social orders take individuals' names and perceptions and destroys them. When Proctor pleads for his name, pleads for his reputation, and for everything else to be taken, it is his moment to take a stand. It is a moment in time where he recognizes that the limits of the Salem social order will not be able to do much else, except to take people's names and drag them through the mud. In pleading for his reputation, Proctor understands the reality of death, the reality of being branded as an "outsider," and what comes with it. Yet, he is defiant in his belief that his "name" is his own. It is this that becomes the most important element by the end of the play.
John Proctor is most concerned at the end of the play with his own good name. He sacrificed his reputation by testifying in open court that he had committed adultery with Abigail Williams, angry at the fact that he had to go that far, and throw away his own good name when he could not have another.
By refusing to confess to witchcraft at the end, and forcing the court to hang him even when they knew by that point that the accusations were a farce allowed him to stand fast on his principles and to take his good name back, in this case, with him to the grave.