9. Peyton Manning
On one hand, Manning’s comeback against the Patriots in the 2006 AFC Championship Game motivated Scott Pioli to go all-out and acquire every available star player in NFL history. On the other hand, it was a painful loss that could have been avoided if the Pats had signed one wide receiver of marginal talent, and it set up the most painful loss in Patriots history the very next year to Manning’s little brother. Manning may end up being beloved in two cities — Indianapolis and Denver — but he will never be welcomed in Boston.