The Friends episode where New York City experiences a blackout is called "The One with the Blackout." This episode is from Season 1, specifically Episode 7. In this episode, a blackout hits New York City, leaving the friends stranded in Monica's apartment, Chandler stuck in an ATM vestibule with a beautiful woman named Victoria, and Ross trying to navigate his way through the city to reach the apartment. The blackout leads to various comedic and romantic situations, making it a memorable episode in the series.