One of the android fan site out there ultimately decide to test the durability of both iPhone 5 and Galaxy S3 by dropping them from various heights. This entire experiment was recorded on a video whose link is given below. The experiment conducted by Android Authority shows proves the fact that Galaxy S3 is more prone drop based damage as compared to iPhone 5.
In the entire test iPhone 5 hardly suffers any damage whereas the plastic body of Galaxy S3 breaks into pieces after dropping from a height of around 4 feet. But in both the phones there is no effect on the functionality at all.
http://www.youtube.com/watch?v=6M5q5TRuAsY&feature=g-logo-xit