Football Outsiders has their DVOA rankings out today or as they explain it…
"Team efficiency ratings… measured by our proprietary Defense-adjusted Value Over Average (DVOA) system that breaks down every single play and compares a team’s performance to the league average based on situation in order to determine value over average."
Anyway, the Giants are #5 overall, the offense is ranked #11, the defense is #2, and special teams is #30. Here is what the top half of the league looks like after week 13: