Right now I am stuck between Gears of War 3 and Portal 2.
Portal 2 had such a tight, refined experience accompanied by enjoyable commentary by GlaDos, Wheatley, and Cave Johnson.
Gears of War 3 did so much more in it's development time, and it did it almost as tight as Portal 2 did. I never broke out laughing over lemons, but I did almost break down into tears.
So... I guess, if I absolutely had to choose, I would say Gears of War 3. Even if they are pretty even in gameplay and story refinements, then graphics are the deciding factor, and...Gears of War 3 just looks baffling.
Currently Working on - Warning: all posts after Midnight Central Time are a form of natural high that occurs due to lack of sleep.