Apart from all the obvious moments which many others have discussed, which arguably defined who we are now (FA cup semi, FA cup final, Newcastle game, numerous big games in 13-14), one of my favourite Yaya memories was last season when he played at Palace.
A lot of people, myself included thought he was done at City (hadn't been close to a team sheet all year), and then all of a sudden he starts and scores twice including an 82nd minute winner. I can remember being equal parts shocked and excited when I saw his name in the starting lineup.
Incredible player.