Rankings:

1. League of Legends - 46.47%

2. PUBG - 8.48%

3. Sudden Attack - 7.56%

4. Fifa Online 4 - 6.97%

5. Overwatch - 5.54%

6. Maple Story - 3.48%

7. StarCraft - 2.25%

8. Dungeon & Figher - 1.93%

9. World of Warcraft - 1.37%

10. Lost Ark - 1.36%

Source

Edit: Since there are a lot of people asking: these stats only refer to internet cafés in Korea aka PC bangs.