I'm just going to leave these here, first come first serve.
Dead Space: Origin: 49LU-86KC-TEB8-T95H-YZQ9 Steam: FI7IN-XHP3P-XZVER
Dead Space 3: Origin: 5EKK-3DU6-6WKU-95RA-66RH
Medal of Honor: Origin: DGXF-9YM7-EGNE-T9LM-WRPU Steam: BD68Q-EVTEC-0HJXX
Not sure how the keys work this time, if both Origin and Steam can be activated or if once one is used the others are invalid. If it's the first case someone can leave a post, I'll add in the Steam versions of the rest of the games later.