The Seahawks haven't looked impressive lately. Barely won against the winless Bucs and the woeful Rams. 18 points away from being 1-4 in their last 5. There is something to be said about the way they manage to win games. Still, if the Bucs and Rams can take them to the wire, the Giants can at the very least can eke out a win. The Seahawks at the beginning of the season were dominant but they've cooled off despite the record. It's not a great match up for the Giants since the one place their vulnerable is rush defense but still, they can be knocked off before the Giants have to play them.
San Fran, in my opinion, is the team to beat in the NFC. Their defense is great and it would take a great game from Eli to put up more than 20 points. To stop their offense, you need to stop the run and actually the Giants have been great at that over the last couple of games. This isn't the worst match up they could face. That would probably be the inconsistent Saints who just lost to the Jets and aren't a lock to make the playoffs.
Either way, the parity in the NFL this season seems to be notable on an all-time basis for professional sports. It truly looks like any team can beat any other team on a given week. Should the Giants enter the playoffs with momentum and have Eli play like has twice before, they have a chance. That's all you could ask for in any season.