Just a short note to add to the excellent answer above: Synge's Playboy of the Western World is hilarious. Synge originally labeled the work a farce in its early stages, and though he eventually dropped the label from the title, the play is still very much a comedy/farce.
Christie Mahon kills his dad, becomes a hero because he kills his dad, then shrinks when his dad shows up still alive. Though there are many sides to the play, as Synge himself said, humor is a big part of why people like it.
In 'The Playboy of the Western World' by J.M. Synge, the author presents a colourful tale that is honest and realistic. Although many Irish audiences were offended by the stark offerings in the play, finding them sometiomes crude and overdone, other audiences found the honesty refreshing because they felt it was truly representative of their lot in life and their issues and concerns. Because J. M. Synge presented this honest realistic portrayal of everyday Irish lives in poetic style, many audiences were able to relate to the material in both a traditional and modern form. The hard living in the Aran Islands was interesting material for most audiences and they responded to its connection with Nature.