Why do you think Akhenaten was more egotistical then the other pharaohs? I mean, he said he is the son of Aten, but the others said they're the sons of Ra. What's the difference?
You're right about the "son of Re." That title goes back to Djedefre of Dynasty 4, 1200 years before Akhenaten ascended to the throne. And Akhenaten wasn't even the first Aten worshiper; his father, Amunhotep III, made it a sort of personal religion and was probably responsible, if unintentionally, for the absolute obsession Akhenaten developed for this hitherto minor deity.
But Akhenaten had the sheer force of will to turn Atenism into the state religion and at the same time abandon and bury so many of the important gods and goddesses that the Egyptians had been worshiping for thousands of years. That alone bears out the kind of robust and perhaps even neurotic ego he possessed.
And it wasn't so simple a matter as mere religious worship. In closing down many important temple complexes and sealing himself and his government off in the new capital he created at Amarna, Akhenaten inflicted unquestionable and serious economic damage on his country and allowed the vassals and foreign concerns of Egypt to break away from Pharaoh's grip. We have cuneiform letters from that time written by Caananite rulers begging Akhenaten to intervene in disturbances taking place in ancient Palastine, and by all accounts Akhenaten seemed to dismiss and ignore them completely.
Akhenanten was no saint. He certainly wasn't the greatest pharaoh ancient Egypt had. But none of that takes away from the fact that this man and his reign constitute one of the most fascinating and intriguing periods of ancient Egypt.
There's no surprise he's your favorite pharaoh. He's many people's favorite pharaoh!