Good film depends of Conflict, Action, and Resolution.
It can be said, a CAR factor.
Four kind of Conflic
1) Conflict with Inner life (Seven Pound - Will Smith)
2) Physical Conflict (Black Hawk Down - All War Films)
3) Nature Conflict (2012)
4) Social Conflict (Charley Willson's War - Tom Hanks)
5) Conflict in Relationship (Mostly bollywood film)
Remember, all conflict has a action and all action has a resolution.
If we want to make a action film with using plot of romantic film, it will flop...
Including all kind of conflict in one films gives success of film but strong storytelling is necessary.
ex, TITANIC, Lord of the Rings