There are three basic approaches to creative writing that can create equally good but considerably different works. One way is to focus on a strong set of characters; another way is to focus on the action or story; and yet another way is to focus on expressing ideas through dialogues. No approach is necessarily better than the others; they are just three different ways to get the ball rolling. Some genres may dictate which approach to use, and most great works do two or three well.
When you create compelling characters, it almost doesn’t matter what situation you put them in – it’s their interactions with each other that drive the story. Some examples of this sort of approach are Orson Scott Card’s Ender series and the TV series Brothers and Sisters. In these family dramas, they could be arguing a bag of chips, and it would still be entertaining because of their personalities and the family dynamic. The advantage of strong characters is that they can sustain a series for quite a long time.
Similar to action movies, some books race along so quickly that it really doesn’t matter who the characters are or what they say – think The Da Vinci Code and (to some extent) Dan Simmons’ Hyperion Cantos. The brisk pace makes it difficult to flesh out characters and dialogues, but it’s not impossible. The downside of focusing primarily on action is that your work may not be particularly memorable.
Dialogue is the biggest way that characters interact, so usually it’s intimately tied to having strong characters. However, some genres like philosophical sci-fi and mystery are particularly dialogue driven without necessarily having strong characters. Dialogue has always been the traditional medium to discuss philosophical ideas (ie. Plato’s dialogues). In mysteries, the real action has already happened (ie. murder, robbery, etc), and the protagonist must talk to people to figure out what happened. Witty or even cheesy dialogue can be very memorable – one of my favorites is the “You can’t handle the truth!” bit from A Few Good Men. Classic.