Good stories spring forth from strong characters. Select a fictional character or a historic figure and interview him/her. Ask them tough questions. Get to know them. At some point a plot will develop from the questions and the answers in the interview.
Here are five interesting people to interview.
Joan of Arc
Vincent van Gogh
Based on an interview with Judas Iscariot I generated this pitch.
Haunted Streets – Contrary to what the world believes Judas Iscariot is not dead—he is cursed. The immortal has wandered in search of emotional refuge. Angels taunt him. Devils follow him. Then he stumbles across the only human older than himself and a chance to redeem his mistake.