Epic's bonanza of Torchlight 2 for free.
Torchlight 2 is currently free on the usual 15 day event. If you've yet to claim an Epic freebie during all this, doing so will get you a $10 coupon for use in the holiday sale. That coupon will refresh every time you use it, too.
Torchlight 2 came out the same year as Diablo 3 – which is, incidentally, preparing for the next Diablo 4 release date, it'll be a great way to fill that time.
There's one more Epic freebie to go this year, and according to the very accurate list that's leaked onto the internet, that last title will be Jurassic World Evolution. Not a bad way to close things out.
For some free GOG games, you can follow those links.