I always thought the novel The Alienist by Caleb Carr was just ripe for adaptation. In the book, a scientist in the late 1800's, who specializes in advanced (for the time) forensic techniques, assembles a team of experts to hunt a serial killer. (Granted, it does cover a lot of the same ground that Murdoch Mysteries does, but I do love that show, and this book had a much more dramatic take on the concept.) I also wouldn't mind seeing a show based on Sue Grafton's Kinsey Milhone books. Or Ed McBane's 87th Precinct, for that matter. (Yeah, I know, they've already made two pilot movies about the 87th that weren't picked up for series. I'd still like to see it, though.) And if we're talking science fiction, Spider Robinson's Callahan's Crosstime Saloon would make a great basis for a Twilight Zone-style anthology series.