What are you looking for and how much do you want to spend? Something to brighten you up, or something to lose yourself in?
If you want something stress free and upbeat, Slime Rancher is on sale right now for like 13 bucks.
Subnautica is also some high quality, low stress entertainment.
You could also try some of the Telltale Games, I recommend Tales from the Borderlands, but it's a little pricey at 27, though it regularly goes on sale for ~10.
Fortnite is of course free.
I've played hundreds of hours of Renowned Explorers: International Society, which is a roguelike with a mix between FTL and Indiana Jones, with a very unique combat system. It's an absolutely charming game, with a great community and replay value.
Pit People is a funny little game with lots of charm, I haven't dug too far into it but I like what I've played.
Of course, classics like The Elder Scrolls and Fallout are options if you need adventure.
If you do want to lose yourself in a universe, Stellaris is a great option, it goes on sale often.
I've been playing some Elder Scrolls: Legends if you feel like a card game, it has a very good amount of free content.
Hope one of those helps you out, I tried to keep it varied, but weird indie strategy games are kind of my thing.