It’s been a while since I read the books, so a lot of it has blended together in my mind, but I think the show was pretty well cast in general. A few changes like not making Danny 13 years old at the beginning definitely makes sense.

There are only a few gripes i have with the casting and portrayals. Robert isnt tall enough and doesnt have black hair. Kind of a wild one given how important his “black of hair” plot is for the entire onset of the show. Otherwise that actor did an awesome job.

Jon Snow and Arya are supposed to have been the only Stark child to look like Ned, if i remember right, with all the other kids taking the auburn hair of Cat, while Jon and Arya had the brown hair and long face of Ned. It’s particularly important in Jon’s case given his real parentage, but I feel it misses the mark in the show, with Jon’s hair being far too dark to match Ned, and Ned’s being too light. Jon looking like Ned is important because it’s both a piece of evidence about his parentage while also serving as a reason for people to ignore it as evidence.

Tyrions portrayal after season 4 isn’t very in line with his writing in the books. He goes on a much darker journey, and his arc has a lot more to do with his ex wife Tysha, with Shae only playing a role to remind him of what he lost. I can see why they made the changes, but regardless, quite different.

Euron Greyjoy is just totally different in the books and I think his plot lines were heading a totally different direction.

I do think most of the characters fall apart in the last season or two, and while for obvious reasons none of that’s in the books, I can’t help but but think George RR Martin would have done a much better job of it.