Edgar Allan Poe thought the short story was superior to the novel. His argument was that since the reader experiences the short story in one sitting, the story will have an uninterupted, and thus deeper, impact on the reader.
I disagree. The scope and depth of a novel can entirely pull a reader into a separate world. The novel offers a unique experience. Frankly, what the short story offers can also be offered by a film, a poem, a piece of music, a visual work of art (I also believe drama to be a unique artform, in the way it is re-interpreted and re-experienced). Taking breaks reading doesn't taint the novel's effect; rather, it is often through these breaks that the novel lingers in the reader. It can have a greater impact because you pull the novel into your own life.
Good films can suck you into a separate world, too. But the film is akin to the short story. It can suck you in for one sitting, and if it is very good, it will still linger with you for a long time.
But a good TV series is like a novel: it has greater scope, greater depth, and your experience with it stretches out across and into your life. You can't follow it all in one sitting; however, because you experience previous episodes, you know somewhat what to expect from this other world, so you can easily be drawn back into it within a few seconds or minutes of viewing.
A good TV series has every reason to be called "art" that a film does. It can pull you into a separate world. It can examine human existence. It can teach lessons. It can inspire. Put all the episodes of The X-Files in a row, and you've got as good a visual sci fi narrative as any film. Watch all the episodes of Nip/Tuck, and you may find yourself inspired to be a better person (whatever that means to you). Watch all the episodes of Six Feet Under (I'm 2 episodes away), and you'll experience a meditation on the meaning of death as good as you can hope to find elsewhere.
Even comedy draws you into its world. When I watch Curb Your Enthusiasm or Seinfeld, I feel I have entered something outside myself, while also entering deeper inside myself.
I don't want to denigrate the short story or film. But I think that a TV series is like a novel--encompassing artistic experiences.