Nouns with superlative adjectives normally have the article the.
‘The Exorcist’ is the scariest movie I have ever seen.
After link verbs, superlative adjectives have the.
I am the greatest.
The cannot be dropped when a superlative is used with a defining expression.
This deal is the cheapest I could find.
But note, we do not use the with superlatives when we compare the same person or thing in different situations.
She works the hardest in the family. (A woman is being compared with other members in her family.)
She works hardest when she is doing something for her family. ( A woman’s work is being compared in different situations.)