The Ironborn may be a miserable pack of pricks, but the decision not to run with their A Feast For Crows storyline in Season 5 still annoyed many fans. Theon's father Balon and sister Yara (Asha in the books) were introduced in Season 2 to serve as the catalyst for the eldest living Greyjoy boy betraying his "brother" and King, Robb Stark. When Theon found himself a prisoner of the Boltons, his sister attempted a rescue, only to come to the conclusion that Theon (now "Reek") was beyond saving and... that was that. That was the last we saw of Yara and her kin on the show, but there's a lot more going on in the novels should they choose to adapt it.
For one, Balon is pushing up daisies (well, pebbles!) after Melisandre's little trick with the leeches leads him to fall to his death near his home on Pyke. No mention was made of this on the show so it's assumed he's still alive. His demise leads to a "Kingsmoot" which sees his even more ruthless brothers Aeron, Euron and Victarion (along with Yara) vying for the crown.
Apparently the Greyjoys were shelved in favour of Dorne, but they obviously have a major part to play in future novels so it'll be interesting to see if they make a comeback in Season 6.
Freelance writer/editor/reviewer. Resides in Ireland, where it rains 11 out 12 months of the year, and the grumpy bastard wouldn't have it any other way. He has a passion for all things film and comic related, and also dabbles in amateur film making, screenwriting and photography.