I've been watching a lot of film noir lately and one of their key appeals to me is the bare-bones running time. Many are around an hour. I feel a lot of films i see these days are just bloated.

I think "I Love You, Man" was an absolutely hilarious 80 minute movie. Pity it was two hours long. "POTC3" was downright corpulent in its length.

Obviously it depends on the type of movie. I can't imagine David Lynch should ever cut a scence because it doesn't move the plot forward enough, but a scene in "Fast and the Furiouser 6" that dwells on Vin Diesel's childhood lonliness may not be needed.

A fun example is the EE of the LOTR movies. Plainly that extra time wasn't needed to tell the story in a strictly narrative sense. We can debate how much adding it back in enriched the films (I rather like it) but ultimately it comes down to how invested the audience is into the story.