Try not to think of the classes as the limits of what you can build. Think of a character, then find a class or combination of classes that allow you to build that character. Don't shackle your imagination by starting within the framework, but use the framework to support your imagination.
My character Jennara is a Monk only because that was the class that best fit my concept. If you call her a Monk in-character, she shakes her head and looks at you funny, because she's not a Monk in the traditional sense. She's only a Monk by game mechanics.
