If something is the snazziest, it is the most stylish or attractive.
The word snazziest makes people think of fashion, parties, and looking really good.
Examples:
She wore the snazziest dress at the party.
The snazziest car in the lot was bright red.
He has the snazziest shoes in the whole school.
The snazziest hat I've ever seen was covered in glitter.
The snazziest house on the block had a rainbow door.
The snazziest cat at the pet show wore a tiny bow tie.