My Steam library basically only consists of Witcher 3 and Spiritfarer. I also was gifted a Humble Bundle game for Batman Arkham Knight.
I’m debating on getting Elden Ring and Cyberpunk (both without DLC).
Marvel’s Spider-Man and FF7 Interograde also look like a good value right now for 40 bucks total.
You’re getting all kinds of recommendations for Steam games. But what about free games? In desktop mode, the “discovery” app let’s you install programs, including games.
There’s tons of free games. I’ll admit a lot of them aren’t the highest quality. They are mostly open source clones of more popular games.
One game I recommend in particular is Super Tux Kart. (Tux is the mascot of Linux, and SteamOS is Linux based.) It’s a kart racer game. It’s one of the highest quality open source clones out there, though. Great graphics too.
If you own Minecraft, the Prism launcher will allow you to run it in the Deck. Just go into the steam menu in desktop mode and click “add non stream game” to add any apps you install this way to your steam menu. Now they can be launched in handheld mode as well!