However, the most famous cited for this moment is Episode 474 (title varies: "Execution of the Admiral" or "Conqueror's Haki" depending on the sub/dub).

Here’s a concise guide to the specific episode and context for in the One Piece anime. Key Episode Episode 473 – "Wrapping Up the War! The Red Hair Pirates Appear!" (The Haki burst actually occurs in the latter half of Episode 473 and extends into Episode 474.)