The most snobbish or stuck-up out of a group of people.
Being the snobbiest is not a good thing. It means you think you are better than other people.
Examples:
She is the snobbiest person I know.
Out of all the kids, he is the snobbiest.
The snobbiest cat in the neighborhood always walks with its nose in the air.
The snobbiest dog in the park only plays with purebred dogs.
He thinks he's the snobbiest person in the whole world!
The snobbiest bird in the forest only sings for the fanciest people.