There are not that many that go beyond stereotypes and cliches.
Still there are some interesting ones. He is not a hero, but I like the Black Manta as a rutheless villain that lives under the sea. They could have given him some more powers though...
Check out this website for a huge list of black superheroes:
http://www.blacksuperhero.com/exhibits2.cfm
The thing is that I like mysterious heroes that are not just brute force. Even if they are powerful it is nice if they can use some finesse with their powers. Unfortunately many black superheroes are in the "big thug" category, especially older heroes.
Cloak is pretty cool, but he is stereoptypical in other ways (black hero - power over blackness). I still like Cloak a great deal though, he has a unique power and is enigmatic and interesting.
I also like John Stewart Green Lantern, but he looks much cooler when he wears a mask like Hal. I always just liked Green Lantern: cool powers, cool uniform. I like John and Hal the best because they are serious veteran Gls.
I look forward to seeing who other people select.
p.s. (what percentage of black superheroes have "Black" in their names?)