Game of Thrones
1 - 95% of the pilot episode needed to be remade. It wasn't just the script that needed to be changed, some cast members were also replaced as Tamzin Merchant for Emilia Clarke and Jennifer Ehle for Michelle Fairley
2- The first version of the opening was a little different than what you're used to. Instead of showing the map of the series being assembled with dozens of gears, the introduction was driven by a crow. The animal flew over the main locations on the map, such as Winterfell and Black Castle. His journey ended in Porto Real, landing on the Iron Throne.
3 - Do you want to learn to speak like Khal Drogo? The Dothraki language, created by David J. Peterson for the series, has a vocabulary of over 3000 words
4 - Peter Dinklage did not have to audition for the role of Tyrion Lennister. The directors already had it in mind even before the show was released.
5- Ian Whyte played 4 different characters in Game of Thrones: a White Walker, an unnamed giant, Sor Gregor Clegane and giant Wun Wun.
6 – The Red Wedding was based on two real events, Martin used The Black Dinner of 1440, a trap that ended in the murder of two children and the Massacre of Glencoe of 1692, during which soldiers claiming to need shelter due to a full fort slayed their hosts.