Over the past 5-10 years, television has increasingly taken over as the dominant filmed art form in terms of quality. There have certainly been many great theatrical films over that span, and it’s still tough to beat the experience of the big screen, but television’s ability to tell complex tales across multiple seasons and to evolve characters over many years is unique.
I don’t know when the switch came from episodic television that was truly episodic (with each hour or half-hour essentially self-contained) to the complicated mythologies that are so common today. Perhaps it was Twin Peaks or The X-Files, or something earlier that I’ve never seen.