Answer: The Sopranos
Today, we take gorgeous title sequences for granted. We sit down to enjoy high quality programming like Game of Thrones, Westworld, or American Gods, for example. Not only are the shows themselves a fantastic visual feast, but the feast does not start with the first moments of footage from the shows, but even before that with an artfully composed title sequence.
Whether you realize it or not, you’re living in the golden age of title sequences. Historically, they were a rather spartan affair, a combination of a few scenes (if that), the show’s theme song, and maybe a quickly shifting overview of the cast you were about to see (like the introduction of MASH that quickly showed you where you were, in Korea, who you would see, with the cast going about their daily lives on the base).
1999’s hit mob-centered drama The Sopranos changed that. Title screens weren’t just for showing a bit of scenery or splashing the cast in front of you, but for building a tiny story in and of itself that drew the viewers in before the show had even truly started. The Sopranos title sequence not only introduced you to Tony (and in an artful way that showed him in bits and pieces until he fully emerged from his car at the end of the sequence), but it also established the location and tone of the show by tracing his movement through the outskirts of New York City into New Jersey.
It was so important to the director that the show evoke a sense that it was happening in real time that after September 11th, the title sequence was edited to remove the Twin Towers, not just out of respect, but to preserve the sense that the viewer was experiencing the world of The Sopranos as it was unfolding.