Attack on Titan author Hajime Isayama has an interesting list of media inspirations. Visual novel series Muv-Luv, definitely. Jojo's Bizarre Adventure. The Frank Darabont adaptation of Stephen King's The Mist. Actually, less zombie material than you might imagine. He's played Resident Evil, but not seen the Romero movies. Now add to that Game of Thrones. Stated on his blog, Game of Thrones, the HBO adaptations of GRR Martin's novels, is going to be an influence as AoT moves into its final phase.
In mid-November, Isayama started watching Game of Thrones: Seven Kingdoms Senki. 60 hours and six seasons later, he left the whole thing dead on the battlefield. He seems to like just about everything about the show, from its plotting and casting, to the production's budget and ability create a fully realized Dark Ages world, to its ability to humanize even the detestable characters, going into this thoughts on Joffrey and Theon a bit.
He highly recommends the show and suggests that it might shape his own work in some way.
And, he shared illustrations of Davos Seaworth and Jorah Mormont.