One of my favorite mystery authors since college is Sue Grafton. Her alphabet series (from A Is for Alibi to W Is for Wasted, so far) features a strong female protagonist named Kinsey Millhone working as a private investigator in Santa Teresa, a stand-in for Santa Barbara. Grafton weaves lots of personal history about Kinsey into her stories, making the star of her series come alive. Really wonderful reads.
Ideas are easy. Its the execution of ideas that really separates the sheep from the goats.
More on the execution of ideas in another post.