These are the most-owned games on Steam, a digital distribution platform (wiki). This was fascinating to me for a bunch of different reasons. You can come up with your own, I’m sure. Here are the wikis for the games:

• Team Fortress 2 (orange)
• PlayerUnknown’s Battlegrounds (yellow)
• Dota 2 (red)
• Counter-Strike: Global Offensive (blue)
• Unturned (green)

I have played none of these games…