Zabaleta and Nastasic have been great this year...
Aguero has been going through a couple of injuries this year so he has never quite gotten things going because he just hasn't been able to get into a rhythm yet. So while he hasn't performed, there are reasons why that has been so. He'll get things turned around over these next 3-4 months.
Barry and Milner have been great this year too.
Its good to see some of our looked over players to be getting some pub. Granted they are good players in their own right but considering some of the players they play with you wouldn't have expected them to outplay some of them.
Regardless, its because of these guys that we are in 2nd and still in striking distance of United despite not completely clicking on all cylinders this year.