Unlike movies, tv shows offer a whole new dimesion to film. Tv shows offer longterm storytelling, unlike a two hour movie tv shows can put hours into a storyline. In Tv shows you often feel like you have developed a relationship with a chracter which adds a new element to the enjoyment of tv shows. You get to watch a chracter grow and develop through seasons.
Gotham follows Dectective Jim Gordon on his edeavor to keep Gotham safe of its evil villains. Gotham shows how the famous villains we know came to be.
The Flash follows the story of Barry Allen who was struck by lightning and was given the power of superspeed.
DC's Legends Of Tomorrow follows time traveling master Rip Hunter and his team of super heroes and villains to save space and time.
The Arrow follows billionaire Oliver Queen who was stranted on an island for 5 years. He becomes a vigilante to return starling city to its former glory.