On D, besides the obvious usual suspects of Sherm & ET:
Michael Bennett. Without his QB pressures and sacks, 2 of those W's are L's.
Bruce Irvin. Without his big plays (including his first pick, in coverage!!) we don't win the Rams game.
Brandon Browner. Dude has a knack for making big plays at key times. Still smile every time I think of his Pick 6 against the Lombardi-trophy-bound Giants in 2011 for the W. Then his key plays against Cam Newton and the Panthers. Blowing up Wes Welker of the Patriots last year, knocking him out of the game for a few plays. Stuffing running plays.
Definitely some love for Kam too, but I place him in the next group below those other guys in terms of X-factor plays during a game. Of course, that hit on Vernon Davis last year was priceless and in a class by itself.
On offense, the obvious usual suspects are Russell and Marshawn.
Golden Tate is a big-time X-factor player.
Jermaine Kearse has been a HUGE X-factor for us this year. Including blocking a punt on special teams!!
Next group, just barely a notch below:
Doug Baldwin, but in a different way than Tate and Kearse.
Zach Miller
(Sidney Rice)
Next Group:
Luke Willson has shown flashes.