Everybody's a fish out of water. Most movies involve fishes out of water. This is because Hollywood has happened on a quirk of human nature: everybody can relate to this. Everybody can relate to not feeling like they belong.
You are each so unique, audience
Note how in every small-town, even if everybody else is a dumb hick, there is always that one person from there who is pretty cool, this person is either the hero or the loyal sidekick to the hero. Every real life dumb hick who sees that movie will identify with that person. They won't see themselves as being any of the other assholes. The same goes for the ghetto, the large corporate office or any other place where the denizens can be stereotyped. The way you get people to identify with your lead character is to make it clear that they are better than everybody else.
Everybody is the hero of their own little movie life.
When the movie ends the hero must have a girlfriend
Everybody wants a sexual relationship. More than that, sexual relationships are a measure of happiness. You have to fall in love with somebody to be happy in life, and have a good future. You can kill the bad guy, rescue the hostages, save the city from destruction, but you haven't really won, and cannot be truly satisfied unless the audience can see that you are now in a new relationship.
There must be a climactic showdown
People believe that confrontations are are definitive and that when one person emerges as “victor” from a confrontation, this indicates that they are victors in life. You can't really settle anything without a climactic battle to determine who is more dangerous or, in many cases, lucky. The bad guy has to die or get beaten up, what's more the fight has to go on for a really long time so that you know that the good guy really has to work for his pay off. He has to get hurt a lot so that when the bad guy gets blown up, skewered, or has a shipping trailer fall on him you feel relief or even joy.
Revenge is always a good idea
People are naturally vindictive. Even in situations where retaliation is not practical or reasonable, everybody still wants it. You got cut off on the way to work this morning, your boss adopted a certain tone when instructing you, a customer of below-average intellect insulted you. Everybody carries a set of repressed grudges. Seeing somebody act on their grudges on film allows a release of tension and delight in vicarious brutality.