? Are you asking which one is better?
Sicilian Najdorf Variation

The two are difficult to compare... one is for White, the other for Black.
King's Gambit and Najdorf are both openings for aggressive players, both in my small repertoire.

This is my opinion. The King's Gambit is fun to play, energetic, dynamic, and great for the club player. But as you get into the higher rungs, compensation for the pawn becomes smaller. The KG is not a good choice at the higher levels, but perfectly fine for ours. The Sicilian Najdorf is a great counterattacking opening. Black needs to know a lot of theory to stay in the game in the mainlines. While this is a great choice at the master level, it is quite impractical for club players because of it's theory and it's fashionable lines.
Advantages of Sicilian Najdorf Variation against King's Gambit.