Total War: Shogun 2 (PC, 2011)
I loved the Total War strategy games-before Total War: Rome 2 was the biggest disappointment of 2013. TW fans debate over the best game, with the majority saying Rome 1 or Medieval 2. My favourite though, is Shogun 2. The minor mistakes in past games were fixed, and a hell of a lot of polish was put on this game. It worked. The campaign, in which the goal is to rule a feudal Japan plunged into civil war, is nearly flawless. The real-time battles are amazing to look at and to play (I recommend buying the Blood Pack DLC for maximum effect) and it feels like you have genuinely achieved something when you snatch victory from the jaws of defeat with a single, meticulously planned move.
I remember playing this game in Primary Seven and Senior 1, thus bridging that awkward transition between Primary and High school. I still play it in sporadic bursts today, and still have a ton of fun every time.