The CW has been very successful with their DC TV shows. But they started some that never happened. Here I am going to give a list of the shows I found that Warner Bros. cancelled, why they were cancelled, and if they should or should not be revived.
The Graysons (2008)
In 2008, The CW tried to make The Graysons. The show would follow Dick Grayson after his family is murdered, but before he became Batman's sidekick Robin. The studio president Jeff Robinov said “The studio has opted not to go forward with the development of ’The Graysons’ at this time as the concept doesn’t fit the current strategy for the Batman franchise.” Christopher Nolan said he did not like the idea of another Batman story going on while he was directing his Batman trilogy, the Dark Knight Trilogy. Whether the show be revived or not, I am in the middle. The show sounded great, and was very interesting because it was the story of Dick Grayson before he became Robin. So I would say yes, it should be revived.
When the TV show Smallville was coming to an end, The CW wanted another DC Comics TV Show. The Graysons was one of their ideas, but that was scrapped. Then in 2010, The CW started exploring the idea of a series about Raven. But the show didn't go very far, as Warner Bros never green-lit the project. They never gave it an experimental pilot episode. It is unknown why this series was completely shelved, but it would have been great. The show sounded like a cool idea but it shouldn't come back. Raven is a hard character to make a TV show about, and she works better as a team member. She will be in TNT's Titans/Blackbirds, so let's leave her there.
In 2011-2013 The CW tried to make a series about Hourman. But somehow the project never happened. They didn't think it would work as a TV show so they scrapped the idea. Should the show be revived? No. But Hourman is a cool character, he just probably wouldn't make a good TV series. But the character should still be used, and the best place for that would be in a future season of The CW's newest DC Comics TV show, Legends of Tomorrow.
After many tries at a perfect script for the pilot episode, and the announcement of the Flash TV series on The CW, Amazon was cancelled. They couldn't get the script perfect, so they had to cancel it. This show should not be revived, because Wonder Woman will get her debut 2016's Batman v. Superman: Dawn of Justice, then we will see her in her own movie in 2017, titled Wonder Woman.
Young Justice (2013)
After the animated series Young Justice was cancelled after only two seasons, The CW tried to revive the project by making a live action adaptation. It was said that The CW was developing a live action Young Justice series as a teen drama/romance with a superhero twist, featuring both Superboy and Miss Martian as the leads for 2015. Eventually the idea was scrapped, and nothing ever became of the series. And yes, the show should be revived. The animated series only had two seasons and everyone loved them. Then when a live action adaptation was announced fans were very happy to hear the news. Many of the Young Justice characters are not being used in the movies or any other DC TV show, and the series would be great, so CW, please revive the project.
Booster Gold (2014)
When SyFy passed on Greg Berlanti and Andrew Kreisberg's Booster Gold series, The CW picked up the idea, and even said it could connect to the Arrowverse. But eventually the show just stopped, and there has been nothing said about it since its development. The show should be revived though, even if Booster Gold will be in a team-up movie titled Booster Gold and Blue Beetle. Booster Gold would work perfectly in the Arrowverse, especially since the newest Arrow spin-off Legends of Tomorrow will deal with time travel.
These are the TV series I found that The CW wanted to make. There were others that I did not know if The CW were making them or not like Deadman and Blue Beetle.
Do you want any of these shows to come back? Do you want any of the ideas to stay dead? Please, let me know!