I’d recommend POP!_OS. Very easy to install and use and most games I’ve tried to play work without any problems.

Baldur’s Gate 3, mostly. But I’ve been playing Pathfinder Wrath of The Righteous when the others in the group I play with can’t play.

Oh, and some Cities Skylines II here and there. Works reasonably well with the controller, but it’s not perfect.

I really like the Jetbrains Mono font!

Aa for a theme, I set up my Windows theme so it uses a dark theme at X time and a light theme at X time using the task scheduler. I now have Rider set up so it automatically uses the system theme (dark/light) and I am currently using the Solarized themes (I think both for light and dark themes though I’ve been switching my dark theme around a lot to try and find the perfect one so I’m not 100% sure XD). It automatically switches between the two depending on the time of day.