"The fall" and "The stranger" from Albert Camus, arguably the most accessible cornerstones of Existential philosophy, and they really make you think about your

"The fall" and "The stranger" from Albert Camus, arguably the most accessible cornerstones of Existential philosophy, and they really make you think about your position in this world and as a person. The play "no exit" by Sartre is also very interesting, and works well as the audio version by Partially Examined Life (a philosophy podcast).