10/10
I hardly ever rate something as 10/10. It seems hardly anyone does. Most people when asked will rate something a 7/10 (I never accept this answer and insist on a choice of either 6 or 8).
When I think about why I never rate 10/10 it seems to me it's a combination of believing nothing is perfect (there is always something to improve on) as well as some type of signaling of refined taste that allows me to look down on everything (implying I am accustomed to and expecting better; not that I am).
To the first reason, it seems to me there isn't really such thing as 'perfect' ever, either due to 'perfect' being measured on multiple scales and not ever able to hit all of them, or it being subjective, or it being limited by ones imagination or experience. The second comes from a place of falsehood and snobbery that I am ashamed to admit.
I have a friend who, when asked about an experience they had, meal they ate or movie they saw, will almost always answer with 'it was AMAZING'. An he means it. Every time he comes for a party it's the best party I've ever thrown, or the best cocktail he's ever drunk. This exuberance and enthusiasm about life sometimes gets him compared to a puppy or small child, but is seriously loved by those who know him.
I wonder if I started giving more ratings of 10/10 I'd enjoy life more a bit more, as well as bring a bit more light to this often hyper-critical world.