Black Panther. Cage is just okay for me, but I don't see what's so great about him. I do enjoy him in Thunderbolts though.
I think BP is a more interesting character with a lot of flexibility to explore all types of stories, whereas Cage is a bit more limited. Plus, BP has a classic, streamlined costume, whereas Cage's was so bad they don't have him in it anymore, and haven't even cared enough to put him in a costume again. Granted he doesn't need to be in a costume, but it would be nice to have a black superhero actually look like a superhero.
So, if its a question of who I would want to be? The king of one of the most powerful countries in the world, a strong black nation untouched by colonialism, with non-self-hating, self-doubting black folk, a straight up hero who comes home to Storm every night. Or Luke Cage, a guy with a questionable past, a questionable future, and comes home to Jessica Jones. I'm picking BP. BMB's attention be damned.