Peyton Manning is the greatest of all time. Insert him onto any team in history and they're just as good, if not better. Insert any other quarterback you want onto this year's Colts squad and there's a step down after losing Dungy.
And to anyone who says Brady is better than Manning, you're delusional. Brady is overrated, built up by the league's best o-line and most clutch kicker in the game. How many late-game touchdown drives does Brady have? The only one I can think of in the playoffs was after he had already thrown an interception and the DB fumbled it (vs SD a few yrs back). Peyton hasn't had great receivers; he's made good receivers look great. Otherwise, someone would have given Harrison a shot this year. If you need 3 pts to win, Brady might be your guy, but if it's a touchdown, you want Elway or Manning.