Fun games?

I was ban for 14 days which is fair, i deserve it. I won't make that mistake again. But until i'm no longer banned anyone have some game suggestions i should play until i'm able to play league? I have 4gb of ram but only use 2-3gb. I don't have money to spend so it needs to be free. I also don't like games like Blade and Soul. If it's a steam game i might be able to download it for free even if it's not a free game. Hopefully you guy's can help me out