Hawkman and Hawkwoman
Bring back Shayera and put the two in a book they headline together already, DC. Heck, make it Hawkwoman and Hawkman, even; it doesn't matter. Rejuvenate the archeological underpinnings of the characters and use it as the springboard for stories spanning from an ancient tomb in Egypt to the far reaches of space. Unlike a lot of super heroes there's virtually no limit to the scope of adventures these two could be having in today's DCU. The biggest thing for me, though, is that they both deserve to be having them. The Hawks are always stronger together than they are apart, both in-universe and from a marketing standpoint.