Some of its going to be personal depending how you lie your image.
For movies, with Dolby vision I like like cinema home with the AI settings on. For other content generally filmaker mode but will flick through the pair of ISF presets, ISF bright if you want a bit more pop in some content without blowing things totally blue, I think they have done a largely good job with the presets.
For gaming, going to be personal preference outside of enabling 120hz @ 4k, VRR etc. On RGB Full 12bit vs YCbCr 4:4:4 12bit I have never found a solid answer to go for one or the other and tbh difference largely unnoticeable to me so pick one and stick to it. Outside of that, most defaults I do generally set OLED Brightness down to 50 or so, more to do with less blasting my face with light day in day out. Contrast and black level to 50 and black and white stabiliser to 10. In all a pretty base picture and as I say tweak how you want really is what it comes down too. You then get to HGIG vs DTM vs off. Everyone has a varied opinion here, usually will flick between it on games and see how it fares usually.
As I say, everyone will have a varied opinion to what they like so just experiment IMO