I think the responsible pick would be Jordan Hill. We lack big men. If we could grab Jordan Hill and BJ Mullens that would really help us long term upfront. I still think our WORST problem is size.
I would save the money on David Lee in this case--try to facilitate a S+T for a 2010 1st round pick for both Nate and Lee
Taking Jordan Hill, at the number 3 pick to me, is a reach. You don't just take a big for the sake of getting one. Yes size is a need on this team, however so is basically every position on this team besides SF, and maybe PF (depending on Lee's situation). Hill would NEVER go top 5 in a stronger draft, he is only ranked where he is because of how week this draft is for bigs. Just my opinion, but I think Hill has amonst the highest bust potential in this draft.
Based on how I rank this draft today I would go James Harden at 3, assuming Rubio is gone. This team needs a SG and Harden while not a superstar talent, can be a great number 2/3 scorer on a good team. He is a very good shooter and good passer for his position. He also has the leadership and work ethic we all say the Knicks so desperatly need. Not a flashy pick, but he will in my mind almost certainly be an effective one.