These are the best documentaries I’ve found so far on ISIS
City of Ghosts
The take over of Raqqa, and the journalists risking their lives to spread the word.
ISIS: Deserters Speak Out
Militants who left ISIS speak out on why they joined, and which beliefs they still hold. Also covers those who help them escape, and the considerations that must be made on whether or not they are actually able to assimilate.
Documentary about an Australian who joined ISIS.
Defeating ISIS: The Impossible Coalition
A french journalist flies to the war zone to try and undercover the solution to the issue from his french perspective, from the militants perspective, and from the generals perspectives.