Tutankhamun himself didn't have a terribly interesting life or reign, but the circumstances surrounding him is easily one of the most fascinating stories from ancient Egypt. His father was Akhenaten, easily the most bizarre pharaoh - he basically forsook running the kingdom in favor of starting a cult out in the middle of nowhere. His religion was the first known monotheistic one and he drastically changed the art and practices of what was arguably the most conservative culture that there has ever been. Akhenaten's wife (not Tutankhamun's mother) was Nefertiti, who's bust is one of the most iconic symbols of Egypt.
After Akhenaten's death, Tutankhamun and his sister / wife, Ankhesenamun, were too young to rule so the vizier, named Ay, took over and basically tried to undo what Akhenaten had done. The "amun" at the end of the two children's names is significant - Amun was the most worshiped god of the old religion, Tut's father's god was called the Aten. Tut's birth name was Tutankhaten, and the change came with a lot of reversals of his father's religious policies.
For a long time Tutankhamun was believed to have been murdered, but I guess that's in dispute now. Regardless, we have a heartbreaking letter from just after his death sent by his sister / wife to the Hittite king. Remember that Ay, in his seventies, has been ruling the country unofficially for the last nine years, that Egypt was the most powerful country in the world at this time, that the Hittites were traditional enemies of Egypt, and that Ankhesenamun, now eighteen and alone, is the only surviving member of the pure royal bloodline. This is from memory, so don't get mad if it's slightly off:
My husband is dead and I have no sons. I understand that you have many - send me one of yours and I will marry him and make him king of Egypt. Never will I marry a servant.
I am afraid.
A Hittite prince was sent, and he and his retinue were murdered en route. The only other record that we have of Ankhesenamun is her name and Ay's written together in way that signifies that they were married. Ay becomes the next pharaoh, and she disappears after this.