Bioshock and Assassin's creed were great, but personally the biggest twist for me was Modern Warfare 2. Honestly, I was NOT expecting
Everyone seems to Hate MW2's campaign, I love every minute of it.
Shepherd to shoot you and Ghost. It was the best for me because I nearly bloody cried when Ghost shouted "No!" and got shot, and when his body got just tossed next to Roach's. I don't know why, I just really felt sad at that point.