It's hard to explain what year-defining red carpet moments are -- we just know them when we see them. Our jaws drop, our breathing pauses and we take in the superb yet brief style for a split second, knowing that that dress, necklace, outlandish fascinator or manicure will live on in an unforgettable photo.
As 2013 comes to a close, we've rounded up some of the best instances of awe-inspiring red carpet gloriousness.