This poster for the movie, "The Butterfly Effect" is an example of symmetrical design. The butterfly itself is a very symmetrical insect so it would make sense for the poster to be reminiscent of a butterfly. I found it harder to find images of symmetrical design because maybe people find asymmetrical design more interesting.
This Nike ad caught my eye because of the contrast in color and the contrast of the text versus the image. In most cases, color carries more weight but in this ad the black and white image carries more weight than the text. This also makes sense because images carry more weight than text, regardless of color. Your eye goes to the image first and coincides with the message of the ad.