Any fun, free games to download on PC?

I'm looking for games like Minecraft, Gta, but not games like Angry Birds or Solitare.

You should play agar.io

Agar.io, roblox, realm of the mad god, wizard 101, pirate101, team fortress 2, anything free 2 play on steam, etc.

League of legends is really fun you can play agar.io on mobile now