JD, in this thread I wanted to focus on the movies, TV doesn't count, even if they had their fingers in it. It's the movies I feel DC could do better.
Marvel did not wait - they made several B type movies including Captain America, Fantastic Four and The Punisher (and arguably the Blade series).
They tried some TV stuff: The Incredible Hulk, Spider-Man, Daredevil (via the Hulk), Thor (via the Hulk), Doctor Strange and Nick Fury. It was obviously hit or miss and it all stands out as pretty dated and campy to me (although I have a soft spot for that Doctor Strange TV movie - although that might just be sugar coated memories of something I haven't seen in 20+ years).
DC did not play their "big card" early on. Superman: The Movie came out 40 years after the debut of the comic book hero and after the successful George Reeves' TV show (1956) and the serial adventures starring Kirk Allyn (1948/50).
Even Batman predates the 1989 Tim Burton/Michael Keaton romp. There's the obvious Adam West series in the 60's - which spawned a movie in 1966. There was also the 1949 serial Batman and Robin with Robert Lowery and Johnny Duncan.
Let's not forgt some of DC's other blockbusters: Supergirl and Swamp Thing in the early 80s - and Steel, Jonah Hex and Catwoman a little more recently.
...and DC tried their hand at TV as well outside of the above mentioned Batman. We also had a Batgirl TV movie spin-off, a failed Justice League pilot, 2 Legion of Superhero specials and the succesful Wonder Woman series of the 70s - and a failed pilot reboot of WW just a few years ago. Let's not forget Smallville, Lois & Clark, there was a Superboy series in the late 80s/early 90s, The Flash (which brought Mark Hamill back to the screen), Human Target and even the Swamp Thing had a short run. (I have to note the Capt. Marvel/Shazam Kroft TV series of the 70s - which I think might've been a DC character by that point. Which I absolutely loved as a kid, but I'm sure doesn't hold up well at all).
Anyway you look at it, both major comics companies have had their struggles and successes and nothing came over night or early on.