Black Lighting would the the obvious N° 1 choice. I'd also go with:
2- Bronze Tiger - Could Ben Turner actually hurt a man with steel hard skin. I'd sure like to find out.
3 - Booster Gold - I'd love to see the how they'd cover the parallels and differences between these two.
I also wouldn't mind seeing Cage and a larger team of Heroes for Hire cross swords with the Power Company.
Peace