So a buddy of mine and myself, played the co-op of RE6 straight for the last few days.
When it first released, I truly hated the game. My friend convinced me to play it co-op with him and give it a chance. Reluctantly, I did, but something happened along the way that made it really enjoyable. We upped the difficulty, changed some of the settings for aiming and such (making the laser sight instead of reticle for one), and just genuinely had a blast.
I personally don't think the game is GOTY or anything, but there is a lot more strategy (what with all the stamina, melee, and quick shots required in the game) and it was really fun. More so than I had with most other co-op games this year.
For this, I announce that yes, my opinion on a game changed from bad initial impression, to really good, which has rarely happened.