This (I guess) Memorial Day weekend, two blockbuster games are free to play:
Fallout 4
I’d highly recommend FO4; it’s in my opinion the best Fallout game of the series so far due to the customization of your party members, base building and the character tree building options.

Here is the official news, and main website.

And Overwatch.

I haven’t had the opportunity to try this before, but I’ve played its ‘competitor’ (bring on the hate and fanboys) Paladins which is a team-based competitive first-person shooter. There are crazy similarities between the two, but you have to give it to Overwatch, they have oodles of money, being produced by Blizzard *coughWorldofWarcraftcough*, they can do anything and make the game better than any other game out there. Despite this fact, this game may not be for everyone: competitive (vs cooperative) fps games tends to bring out the worst in gamers, can create a toxic environment and make it a bad gameplay experience overall.

Go here for the PC download link and for the FAQ.