Which Defense should I use week 14?

The Redskins are allowing more fantasy points to opposing defenses than all but 6 other teams. They have an anemic offense. That would be a very good play for week 14. The other significant option on your list is Atlanta against Carolina - no one has allowed more fantasypoints to opposing defenses than the Panthers. Tampa has outscored Atlanta so far though. Personally, I would go with Tampa Bay, but it's a close call.