Oh, I missed many others too, the one I regret the most is probably Subanutica. I recently remembered I have a PlayStation account with some games and I saw Subnautica there from their giveaway, but I don't have a PS4/5 to play it. Also Talos Principle was given away in that year, but I didn't know about it way too late.
I also saw a decent deal before on Steam for GTA V for like 10 Euro, but I don't know why I didn't buy it perhaps I didn't have wallet balance or just thought the EGS version was enough.