The rematch. This, in my opinion, is a game that the Titans need to win in order to have any shot at the playoffs. I just think that they will have to beat at least the Colts or Texans at least once, maybe twice, in order to get into good contention come week 17.
The problem with that is, when you give Luck, or any elite-ish quarterbacks, a second look at your defense they will almost certainly take significant advantage. Luck will make the proper adjustments and have his offense clicking.
I almost feel that the Titans have a better chance in snagging their first game, between the two, than this one. I think the Colts manage to handle the Titans at home.