Antigone did the right thing by defileing Creon's strict orders on burying Polynices because the unalterable laws of the gods and our morals are higher than the blasphemous laws of man. Creon gave strict orders not to bury Polynices because he lead a rebellion, which turned to rout, in Thebes against Creon, their omnipotent king. Antigone could not bare to watch her brother become consumed by vultures' talons and dogs. Creon finds out that somebody buried Polynices' body and sent people out to get the person who preformed the burial. Antigone is guilty and although she is to be wed to Creon's son, Haemon. He sentences her to be put in a cave with food and water and let the gods decide what to do with her. He was warned by a blind profit not to do this, but he chooses to anyway, leaving him with a dead son, a dead wife, and self-imposed exile.
Antigone had good reasons for her actions. She did obey the rules of her gods, which were that any dead body must be given a proper burial, with libatations. This would prevent the soul from being lost between worlds forever, along with wine as an offering to the gods (page 518- side note). Nor could Antigone let Creon's edicts go against her morals (lines 392-394). She chooses to share her love, not her hate (line 443). She couldn't bare to see one family member be chosen over the other because of what a king had decided was right, which she contravened. Why condemn somebody who stood up for what they believed in and is now dead for it anyway? Bringing homage to the family was very important to Antigone (line 422-423). .
The gods' laws come before mortal laws in Antigone's point-of-view, which is how I believe also. In death, you will answer to your god and no man will have control of your fate in the world that lies hereafter. Therefore by obeying the gods, hopefully, will result in a happy afterlife, which are what most people strive for in ancient times and now.