Complex sentence: Eugene Wesley "Gene" Roddenberry (August 19,1921--October 24,1991) was an American television screenwriter, producer and futurist, best known for creating the American science fiction series "Star Trek".
Split into simpler sentences: Eugene Wesley "Gene" Roddenberry (August 19,1921--October 24,1991) was an American television screenwriter, producer and futurist. He was best known for creating the American science fiction series "Star Trek".