All hail, George R.R. Martin. He's the man who brought the realm into being, and he's the one man everyone wants to see in the show, but he's yet to take up an inevitable cameo role. The author is responsible for a huge chunk of the show's success, and whenever he wants to star in Westeros, he'll surely be more than welcome to don a robe/tunic/suit of armour. The 67-year-old is probably too busy penning his long-awaited next instalment of the book series, but he'll surely make an appearance at some point. Martin had stepped into the Thrones world for the original Pilot at Daenerys' Dothraki wedding, but alas, those scenes were also cut.