Whatever works for your ears. 

There are so many posts just like this that puzzles me every time I see one. 

As ​@Airgetlam wrote... it is what ever works for you.. because for those who doubt themselves:

Every home is different

Every room is different - this includes wall materials

Layouts may also be different

Furniture and drapery are different

Everyone's audio preferences are different.

YOU are the one listening to YOUR system. What works for me, may not work for you.

Use Trueplay to tune your room, then adjust the levels to what pleases you.

Yes, but you’ve still not said what volume to use

(For those that don’t get sarcasm, this is a good example.) 

New to surround TV viewers usually want to be slacked in the back of the head by the surround. This ‘proves’ that the surround speakers are working. A recent action film is probably the best first play. Later they might want to back off a bit.

As stated by others, only you know what sounds “best” (to you).