Oh jeeze that’s hard to say, it’s between expressions that tell a whole mood or expressions of conflicting emotions
Example of a ‘mood’ expression:
This is a sort of ‘um hello PAY ATTENTION’ expression
GASP
praise be to whomever made this glorious moment happen
meanwhile we have conflicting emotions, good for feels
“this is hard to talk about but i swear there’s a good reason”
trying so hard to not look hurt, but doesn’t know what to do
GOOD FUCKING EXPRESSSIONS!
I personally like expressins that are like “oh great, this person is here” like the face everyone makes when Excalibur enters the room in soul eater
Super grumpy/annoyed expressions also give me life and that’s why most of my protags are angry/easily annoyed grump masters
the perfect duo for getting the full range of emotions are grumps and not so grumps