As everyone has said so far, La Sylphide and Giselle are both very similar in several ways. One way being the plot, both Giselle and La Sylphide have women that were done wrongly by the main male characters. In Giselle, not only was Giselle done wrongly, but also the wife of the main male character. In La Sylphide it’s the same concept just with the Sylph instead of Giselle. Also, both ballets have the realistic first act and then a very mystical second act. Another thing similar is the costumes of the Sylphs and the Willis. They are both white and very light. One very big difference between the two ballets is the Willis and the Sylphs. The willis are very dark, because they are out to seek revenge, whereas the sylphs are not quite as dark, they are more fun. I, myself, prefer the sylphs not only because they are lighter but because I enjoyed their dance routines more. The ending to Giselle was better to me because it was somewhat happier than that of La Sylphide because at least the main male dancer was spared eath and Giselle got to rest peacefully, but in La Sylphide the sylph died and then the main male dancer mourned not only for her but selfishly for everything he had lost, such as his fiancée.