Who Were Some Promising Directors that Slowly Fell Off?

M. Night Shyamalan was the biggest director in the world after Signs, then every movie after sort of got a little bit worse. Hitting his all time low after releasing The Happening.

Neill Blomkamp had everyone's attention with District 9 but never quite lived up to that hype again. I'm not even sure what his last movie he put out was.

Who were some most watched directors who fumbled the ball.