The reason why he became famous is his tomb: complete with his mummy and treasures left untouched for thousands of years. Ever since this lost Pharaoh's tomb full of treasure was found, millions of people have gazed upon him and his treasures. Please note that it is almost impossible to find a Pharaoh's tomb complete with its treasures, due to the infamous grave robbers.
Despite his claim to fame for being the only Pharaoh who had his tomb left untouched for thousands of years, I find his life story to be very intriguing too. Not to mention the infamous curse of Tutankhamun.