What are the most popular plot holes in your favorite movies?

A movie requires too much effort, and perfection, because everything that goes on in that movie is for the audience and if they are unsatisfied with it, then it failed the purpose.

Similarly, there are some unsynced details in some movies which we call " PLOT HOLES" which actually spoil the whole efefct of the movie with its bluntless and obviouness!

Comment the most ridiculous plot holes in your favourite movies and discuss how it should have been covered up to make the movie better?