Quarterback. If you believe he's truly "the guy" give up three first round picks and a couple of thirds. If he IS the guy, you win because you have your quarterback, the most important piece of the team. If he isn't the guy, then you screwed up. But who won't you be able to draft? Who cares? It doesn't matter if you have your guy. Do you do that for a WR? Probably not. A DE? Maybe but probably not. The only position you make a move like that is for a QB. Because without one, your chances of winning it all diminishes greatly.