D&D had to trim a lot of fat off from certain characters in the books and into the show. The biggest complaint I see in the YT community always boils down into three major things.

 

1. The lack of story and development in Dorne with the Sand Snakes and the rest of the Martell plots. It's more interesting in the books for certain.

 

2. Too much screen time for Sam and Gilly. This to me is an interesting bone to pick. I don't mind their story. As long as it leads somewhere worth value in the grand scheme of things. With Sam running off with Heartsbane, his father's Valyrian greatsword. I'd imagine at some point it becomes of use. But many fans complain that the amount of filler that they've provided over the years could have been better served to portray more of what was going on in Dorne.

 

3. Aegon Targaryen. This is another interesting bone that's been picked. Most fans or book readers now assume that Aegon's entire story line is a sham. And that it won't have any major bearing on the story line. With that said. I think D&D already proved it. There is now no point in introducing this character if Yara and Theon have met Daenerys and have sworn fealty to her. 

 

It doesn't really bother me so much to be quite honest though. My only biggest complaint was the portrayal of Stannis in the show Vs. the books. Stannis' character was completely derailed in the show. In the books he's basically a more staunch and stern version of Neddard Stark. Whatever happens to Shireen remains to be seen. The other spin I would have liked to have seen in the show compared to the books was the revelation of Mance Rayder being body swapped with Rattleshirt thanks to Mel's magic. And obviously the return of Catleyn Stark as Lady Stoneheart. 

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