As much as I want someone young and exciting, I equally want someone who makes good game-day decisions and knows how to be a head coach. So, a retread, while probably not exciting, at least knows how to be a head coach already. A young coordinator, while exciting, may force us to endure another few years of on-the-job training, which will drive me absolutely nuts.
Best of all would be an exciting head coach (I am even OK with a successful D-II guy) that knows how to recruit, how to gameplan, and how to make in-game decisions and adjustments. Second to that would be a very good coordinator or an established "retread". But whoever it is better be pretty good at building up a program, as opposed to just maintaining one at a high level.