Ed and Lorraine Warren

Ed and Lorraine Warren have recently been in the spotlight due to their portrayal in the Conjuring movies, being played by Vera Farmiga and Patrick Wilson.
Ed was a self proclaimed demonologist and Lorraine a medium. They travelled all over the world, investigating some of the most prominent hauntings, including the Amityville house, the Enfield poltergeist and investigation into a doll called Annabelle which was said to be possessed by a spirit.
Experts argue that the couple were charlatans, out to make a name for themselves, but being tied to the cases that they were, and through founding the New England Society of Psychic Research, they became famous in their own right. 
Ed passed away in 2006, but Lorraine is still alive today. In their time, they investigated over 10,000 cases.