After GOG pulled their "site closure" bullshit in 2010 I made a point to download an offline copy of every game I owned.

It's, uh, more than I expected:

Some of that volume of data is from multiple copies of a single game. For example, I bought Baldur's Gate 3 when it was first announced in 2020, and I've preserved all the various versions that I've downloaded.

And since it's GOG, they're all DRM-free.