The New England Patriots are 21-point favorites over the Indianapolis Colts on Sunday, a game that was flexed out of the Sunday Night Football spot. (Obviously the NFL thought Peyton Manning would be playing.)
If that seems like a big line, you're right. It's one of the biggest ever, actually. The Patriots' 21-point line is the highest since they ran the table on the 2007 regular season. Those '07 Patriots are tied with the '93 49ers for the largest point spread (via Pregame.com): 23.5 points. New England's came in Week 12 of the '07 season against the Patriots while the 49ers were 23.5 favorites over the Bengals 18 years ago.
Here's a list of all the point spreads of 20 points or more since 1978 (per Pregame.com) with the actual margin of victory in parentheses:
2007 Eagles vs. Patriots: 23.5 (3)
1993 Bengals vs. 49ers: 23.5 (13)
2007 Dolphins vs. Patriots: 22 (21)
2007 Jets vs. Patriots: 21.5 (10)