On the basis all those with the better records win in the lead up to week 18, or the home side where the records are identical, which rarely happens (I mean, I think the Bengals will beat the Broncos)...
Sunday Night Football has to be Vikings at Lions, in a winner takes the NFC North and the first seed. Nothing that happens elsewhere will have an impact on the game.
Seahawks-Rams on Saturday night with the winner taking the NFC West. I'm not sure if that's a possibility should both win in week 17 or if the Rams claim the West on tiebreaker if they beat the Cardinals. Saints at Buccaneers as the early game? If the Bucs win, they would take the NFC South in this scenario. If not, it opens the door for the Falcons.
The AFC play off battle (games involving Broncos, Colts and Dolphins) might get the 1pm Sunday slot, with the AFC North taking Sunday late.