DRM-free store GOG has launched a huge Spring Sale with thousand of games going real cheap. They've also put the Witcher Goodies Collection on a 48 hour giveaway which has art, books, soundtracks and such (no games in it).
They've sorted out a bunch of big collections for this sale like:
XCOM 2 also released on GOG today, sadly only for Windows. I spoke to Feral Interactive, who ported it to Linux and they told me today "We do not have any plans to distribute our games through GOG. If this changes, we'll make announcements through our usual channels.". A real shame, so if you want Feral's Linux ports it's Steam only.
See all the deals over on GOG.com.
The GOG Spring Sale runs until March 30th, 2 PM UTC.