3. Coldhands
Coldhands, everyones favorite mysterious elk rider beyond the wall, deserves some screen time . Not only would he be a great character to see on screen, but it would also most likely mean more screentime for Samwell's storyline. Halfway through the book, Sam and Gilly are saved by a strange wandering man with black, cold hands and a mysterious power over birds. The dude commands an army of ravens, how badass can you get? In the text, Sam implies that in unlike other wights, Coldhands does not have blue eyes, even though he is most likely dead - which rules out the possibility of him being some generic, throw-away creepy dead guy from beyond the wall. He shows up again later in book 5 to help guide Bran, Meera, Jojen and Hodor beyond the Wall. It may be possible that they move parts of this storyline up sooner to either season 3 or 4. I realize it's difficult to introduce an audience to so many new characters each season, and no one wants to be overloaded and confused with minor characters, but it would be a shame not to see Coldhands at all.