1UP has created a top list of the best video game glitches, you can enjoy it over here. Here are the backward flying dragons from Skyrim:
Skyrim had no shortage of glitches, ranging from the hilarious to the absolutely miserable. The backwards dragons fall more in the funny category, and have the unique distinction of being the direct result of a patch meant to fix other glitches. Apparently Bethesda's efforts only made the situation worse, because it ripped yet another hole in the game's already tenuous fabric. This glitch has since been fixed, though some people have reported seeing them occasionally. Now we just want backwards dragons to be a menu option so we can play the whole game that way.