Approximately 30 free games are up for grabs over on GOG. Unfortunately the link for Gwent (Witcher Card Game) seems to be broken. Other than that, this collection is mostly old games and not all of them are any good. But what the heck, they’re free.
TR
Psssh no NWN EE, tho.
I got word that one of the Tomb Raider games was free over on steam. So I took a look. Turns out it is a playable demo (I don’t do demos any more). However, I did notice that the majority of the actual tomb raider games are on sale at around 70 pence (£0.70) each currently.
TR
BTW Beneath a Steel Sky and Lure of the Temptress can also (among other games) be grabbed with no registration from the source - here.
Tiberian Sun and some other freeware Westwood games are also legally available: click me.
Promoting the release of Command & Conquer 4 EA released Tiberian Sun as freeware in 2010. It is therefore legal to download.
Psst, Khajit, tfu, I mean werelynx haz wareezzz.
https://www.reddit.com/r/FreeGamesOnSteam/
https://www.reddit.com/r/FreeGameFindings/
Those two have quite often good games, especially now with the pandemic happening. I can recommend Stanley’s Parable on Epic store especially.
Little update on the Tomb Raider game. I literally got an email from the publisher and a news item when I launched steam - both of them this morning. So I now have copies of 2 Tomb Raider games for free. The main Tomb Raider game is the 2013 reboot of the series. So yea, TR now has TR for free 
TR