Learn Spanish (Latin America): Lo mejor del humorista es su ingenio para el remate. - The best thing about the comedian is his wit for the punchline.

Lo is the neuter article. When combined with an adjective like mejor, it turns the adjective into an abstract noun meaning "the best thing" or "that which is best". If you were to use el mejor, it would mean "the best one", referring back to a specific masculine noun.

Since humorista ends in an "-a", why do we use del instead of de la?

Nouns ending in -ista that refer to professions or people (like turista or dentista) use the exact same form for both men and women. The article is what tells us the person's gender. Because we use the masculine article el here, which contracts with de to form del, we know this specific comedian is a man.

Does the word remate always mean "punchline"?

No, remate broadly refers to the conclusion, finishing touch, or culmination of an action. In the context of jokes and comedy, it translates perfectly to "punchline". In other everyday contexts, it can mean a clearance sale, an auction, or even a shot on goal in soccer!

How could we use todo un or toda una to emphasize a noun in this context?