GS writes: Sub-plots are meant as the foil to the main plot. They might provide comic relief, they might deal with the theme from another perspective, they might let the characters rest between the main events, or at worst, fillers. But what they all have in common is that they are secondary to the main plot, and therefore less interesting and meaningful, yes?
Not always. Sometimes the sideplots happen to be more interesting or meaningful than the main ones. Here are 10 examples.