If you want a good story game, NieR Replicant and NieR Automata are phenominal (Automata is a sequel but both are standalone games so you can play either). Shameless plug of the NieR Lemmy.
Rain World is an incredible work of art. Hard as hell but genuinely an amazing experience unlike others and I highly recommend it, and the DLC is the single best DLC I've ever seen for any video game (and I haven't even finished the DLC despite spending tens of hours on it).
For some fun multiplayer games if you have friends who will grab a copy for themselves too, Don't Starve Together, Stick Fight: The Game, Rounds, and Rubber Bandits are all decent options.
If you somehow don't have Garry's Mod, it's five dollars. Just get it. Just trust me.
And if you like visual novels or just want an absolutely beautiful and horrific story, all chapters of Higarushi are on a mega sale right now.