In addition to Williams, I think Rueben Randle is worth a mention. Randle had 8 receptions for 89 yards and was a factor in the red zone against Washington in Week 4 even though it was Larry Donnell who stole the show.
Randle had a touchdown knocked from his hands on a fluky play that turned into an interception, but he also had a 12-yard reception to get the Giants in that position in the first place. Against the Falcons, there should be points to go around, and while the Giants offense has more targets than initially expected, Randle should be able to turn them into some worthwhile fantasy points if he gets another 10 targets, his Week 4 total, in this game.