8. Sherlock Holmes
Based on the mystery novels of Sir Arthur Conan Doyle, the character has become one of the most iconic figures in literature, film, and television. He has been featured in multiple studio films and television shows in recent years—both Robert Downey Jr. and Benedict Cumberbatch have played him on the big screen and on television.
There are certain iterations and characters from the series that are still under copyright, but the core character of Holmes himself is still readily available for writers to deconstruct and reconstruct under their own creative renditions.