I love Denizel Washington in "Deja Vu", which was excellent science fiction.
He is also fantastic in the numerous fantasy roles in which he stared, such as "Book of Eli", and "Fallen", etc.
Will Smith was the star of "Independence day", which was a great movie, but I absolutely loved him in "I Robot."
Chiwetel Ejiofor was just about the most awesomest bad guy i've ever seen in a Sci-Fi movie. He combined sophistication and class, with awesome physical ability. I thought they should have caste him as James Bond. He would make an excellent Bond.
And who can forget Lawrence Fishburn as "Morpheus" in "The Matrix? Not the lead, but still a d@mn fine role.
Of Course, Vin Diesel ("Riddick") and "The Rock" ("Doom") are half black, but they have both done quite well as leading men in Sci-Fi roles.
And of course there is Samuel L. Jackson and Billy Dee Williams playing significant roles in Star Wars, but not really in leading roles.
I haven't seen the new Star Wars yet. I'll probably see it next week. I shall not be surprised to see a very excellent portrayal of the leading role by John Boyega.
I would like to go into occasions of other great black actors in leading science fiction roles but this message is long enough already.