J. R. DePriest 
:EA DATA. SF:#DeadCells runs great if you like Roguelikes / lites (I can't keep them straight).
Many ARPGs and isometric RPGs run really well.
#PillarsOfEternity, #DivnityOriginalSin, and their sequels run well. #Tyranny runs okay. #VictorVran runs well.
I've played 170 hours of #BaldursGate3 on my SteamDeck.
Some First Person Shooters work well on it, but those make me motion sick so I cannot play them.
#ElderScrollsOnline runs remarkably well on it but you have to do a little tweaking.
Also, there's a reason #VampireSurvivors is consistently the number one game on SteamDeck. It runs like it was made for it.
Oh, you probably want this website if you don't already have it: https://www.protondb.com
It lets you know the best settings and workarounds for many, many games.