I'm a fan of the sandwich approach, which I was taught in fifth grade and have practiced ever since. For this technique, the bottom of the cupcake is twisted off and inverted onto the top, thus sandwiching the frosting between the two halves. This provides an even balance of frosting and cake in each bite, and (theoretically) minimizes sticky fingers and general messiness.
But we each have our own favorite method of enjoyment, each just as good as the last. What's your preferred cupcake-eating strategy?