Red Hood
He does the voice for Jason Todd in the DC animated film Batman: Under the Red Hood. After Batman vs Superman, it would be nice to get Jason Todd's storyline in a Batman standalone film. Jensen Ackles would be ideal, having the voice, the acting chops, and the image of what a reanimated Jason Todd.
Considering his history with the character he is the best option, and could become a staple in the Bat-family and the DC cinematic universe.