As a Salem resident and one-man show, Rory O'Brien knows the back alleys and intriguing stories about Salem. His storytelling style and Magic Lantern projections provide the history while letting Salem's own special aura shine through. His tour not only takes you to the places where events happened but also provides visuals so you get a deeper understanding of the people involved and what they experienced (witchcraft! murder! wrong side of the law!).
I'd definitely recommend Salem On Foot Walking Tours. After all, there are so many tours and tour guides in Salem, especially in October. You want someone who has done the research and can answer your questions, not someone relying on a script.