Notamoosen

If you’re looking for a challenge you could try FreeBSD. While not Linux it’s still unix like and can provide a great learning experience. I believe they have retroarch in their packages, and I’ve seen videos of people getting Steam working. They provide excellent documentation on their OS as a whole.

Do movies getting the Rifftrax treatment count? If so, then Birdemic.

Lots of great options here. Just wanted to add it may be worth using KDE if they’re transitioning from Windows. I try and get the look visually close to what they previously had so they’re not fighting against muscle memory.

Proton has a free package with unlimited bandwidth. It doesn’t offer as many countries or advanced features but it works just fine.