For me good results would be all A*s and 8s with maybe 1 A max. I would be over the moon with any 9s, but anything below 8s/ A*s would probably make me feel a bit disappointed in myself (which is pretty ridiculous, yet I know I'm capable of getting those grades).
That's in terms of myself. For others, I just think anything worked hard for is good. But if I am going to be completely objective and honest, I'd say anything like mostly As and Bs is 'good' in my eyes.
Good luck for results day everybody!