The only game changer I have had is my coaches get some skill points. Didn't notice the increase though.
Before I started my season with Dallas, I went into player management and replaced all the good players with the worst free agent for that position. I kept hold of Romo, Ware and T.O though just so I could win a few games to avoid getting sacked.
I run the Steelers Smashmouth and Raiders Rover books. The 'Middle Blitz' from the Raiders book is shut down material. I finished 6-10.
In the off-season the I signed Rob Ryan as DC, John Harbaugh as STC and Jim Caldwell as QBC.
I don't usually sign the big free agents but Ravens had cleaned house by releasing Ray Lewis and Terrell Suggs... Had sign Ray. 2 years - $19m
I had the 14th pick in the Rambis/Sweetney draft. Throughout the season I had fell in love with WR Jamaar Kidd. The way Schefter talked about him, I had to have him. Traded up from 15 to 5 and drafted him. He is not producing though so far, 4 pre-season games and 2 regular season and he has caught 4 balls.
EDIT: I just got a game changer in pre-season. "Unexpected Injury: Marc Colombo has cut his hand trying to open NFL Head Coach 09 off the field" lol