Time to do a Nightwing (Dick Grayson) flick.... that would make a hell of a franchise if done correctly.
How about the Azrael, Jean Paul Valley storyline. Especially if Batman gets his ass kicked by Bane in this new movie.
agreed.
a solid hollywood director could easily make another trilogy of movies pitting Nightwing against several DC villains.... not named 'The Joker'.
including....
- azrael (jean paul valley stories)
- killer croc
- bolt
- deadshot
- heat wave
- victor zsasz
- lady shiva
- or the entire league of assassins
Using azrael is a good bet.... but lady shiva has the BIGGEST money-making potential, imo.
having a VERY FORMIDABLE female villain... as the lead.. could break the bank @ the box office.
seriously.
especially if they cast a sexy female actress...
- who could do 'most' of her own stunts...
- had decent 'hand-to-hand' combat skills
- looked 'believable' using various weapons & guns
- and gave a solid acting performance
overall, the character should be a deadly version of 'trinity' from the matrix (without the sci-fi special efx).... combined with a 'criminal mastermind'.... almost on the joker's level.
Think Trinity + Keiser Soze = Lady Shiva 
Then think about her 'backstory'...
"Lady Shiva is most likely the deadliest assassin in the DC Universe. Shiva has trained Batman and has also trained the third Robin, Tim Drake. Shiva's daughter, Cassandra Cain, would later become the second Batgirl."
These fun-facts ALONE would sell MILLIONS of tickets to the 'mall rats'.
Plus adults would also watch... as long as the story was not corny.
My lady shiva casting 'short list' would include:
alice braga
carrie ann moss
rhona mitra
Maggie Q
michelle rodriguez