16. XCOM®: Enemy Within
When XCOM: Enemy Unknown was released in 2012, it took the gaming world by storm and became a must own game for every strategy game enthusiast. XCOM®: Enemy Within is a standalone expansion for the game, and brings tons of new content and missions. The goal of the game is simple: defend the Earth against aliens. You’ll have to pay a significant amount of money to own it, but it is worth it.
