I've read all the books, so I'm gonna try really hard to not spoil anything from those, and just concentrate on the show.
I think that the show has done an amazing job overall in bringing George R.R. Martin's sprawling, intense crazy fantastical series to screen. There are changes, most of them I get why, others don't bother me much as someone who read each book just once and doesn't have all the details memorized. The only change that has bothered me is the character Robb is falling in love with. I don't get why they changed Jeyne. Don't get it. Don't like it. It's not Charlie Chaplin's granddaughter's fault (hee, I always get a kick out of that when I see Oona Chaplin in anything). She's wonderful. I just wish they had made her Jeyne! (Yes, that is book-related, but it's past what happened in the book per the series' timeline.)
There is a LOT of profanity, sex and violence in the books. A LOT. A LOT LOT LOT. HBO does not scrimp here, however, they do tend to focus on female nudity way more than male. Although there has been some full frontal male nudity, and they did have some male/male interaction -- not as much as some wanted though. That homosexual relationship was more hinted at in the book rather than flat-out shown as it is in the show. I don't have a problem with the profanity, sex or violence, so it doesn't bother me.
If you're squeamish, I don't think there's any obvious, stomach-churning violence, more the cut/look away implication of stomach-churning violence. But again, it doesn't bother me at all, so my threshold may be different. ( To give you an idea of my brand of what I consider not squeamishly violent -- I didn't understand why everyone talked about the violence in Sin City, it was fine for me. It was there, but not in your face and I felt that it was left to the imagination mostly through the use of comic-book stylings and color.) The sexuality -- especially in regards to the "sexposition," which is essentially lots of exposition given to the viewers while sexytiems are happening -- doesn't bother me either.
Even the infamous sexposition scene where Littlefinger talked about his grand plans, etc., while two whores went down on each other, showing him (the brothel owner) that they knew how to do their jobs. The reason I didn't have an issue with it is because I did feel it told us about who Littlefinger was as a player, and also the life that those without power have to live. But I am quite aware that I'm very much in the minority. Bottom-line, yeah, I don't have a problem with the sex, violence, profanity.
CHARACTERS --
Arya Stark -- (see icon) In the books, Tyrion is my favorite character, while Arya is my second-favorite. In the series' it's reversed which surprised me at first because of how awesome the transfer from page to screen in Tyrion. However, Maisie Williams as Arya is just so spot-on perfect, and her chemistry/interaction with everyone is top-notch. Right now, she's sharing the majority of her scenes with Charles Dance's Tywin. Dance is a well-accomplished, quite acclaimed actor and Williams is absolutely holding her own with him. She's amazing, and she brings everything that I love about Arya to life.
Tyrion -- Awesome. I know some hate him, consider him a misogynistic pig (never mind that outside of Ned Stark (and Gendry), he's probably the least misogynistic male on the show), but I adore him. Peter Dinklage was always considered the only choice to play Tyrion, based, yes, in large part because he's the only current well-known little person actor, but putting that aside, he's an amazing actor and anyone who loves Tyrion, and knows of Dinklage's talent knew that he would be able to bring all of the complexity/vulnerability and every other side of Tyrion to light. And he has done just that.
[Quick book spoilers] ARRGH! Seriously, people pissing all over him for his continual "where do whores go?" in the last book drive me mad with reading comprehension fail. Tyrion is not asking that because he's a misogynistic pig, he is trying to figure out where the hell Tysha (his first wife, who he found out did love him) could possibly be. Before his father died, Tyrion asked where Tysha was and his father told him that she was wherever whores go. Yes, he's being literal in asking it, but it's deeper than just the question, it's about the existential pain that it all embodies. He wants to know where whores go so he can find Tysha, and damn, what does this say about his life? Sorry, mini-vent I had to get out.
Jamie -- Honestly, I don't know that I would have him here if I didn't love him from the books, but I do, and Nicolaj Coster-Waldau does a great job showing me what I do love about book-Jamie.
Brienne -- Same for her (so far). As we've really just been introduced to her, the awesome of book-Brienne hopefully will make its presence known.
Gendry -- I liked him in the books, but he wasn't a favorite. However, the actor, Joseph Dempsie, has done a wonderful job in bringing Gendry to life for me. And it doesn't hurt that he has great chemistry with William's Arya. I'm not gonna lie, I totally shipped the possibility of them in the books. I even MORE ship them in the series. Yeah, totally.
Cersei -- I like Cersei in the show better than the books pretty much because of the flawlessness of Lena Headey.
Varys -- Perfect casting leading to a perfect good/bad ambiguous character. So much love.
Jon -- I like him better in the book, and I do think it's because as likable and good as Kit Harrington is, he hasn't shown me that inner core of strength that I love in Jon.
Of the other characters, I like Robb -- such a bigger character in the series than he is in the books, Catelyn, Jon, Samwell, Renly (sob), Margery -- a more detailed character in the series than the book, Robert, Ned, Sansa -- who I disliked in the books, but I like her in the show because Sophie Turner gets across the vulnerability and complexity that I did feel was missing in the books. Logically I got why Sansa was as she was, but I just didn't feel for her. Turner makes me do so.
I don't really dislike anyone (well, that I'm not supposed to -- looking at you, Joffrey), but these are the ones I love or like the most.
ACTING --
I already mentioned above how fantastic Williams, Dinklage, Dempsie, Headey and Turner are. I think all of the acting is very good to great, with one glaring exception. *sigh* I liked Emilia Clarke's Dany at first (and she's actually my third favorite character in the book (Tyrion, Arya, Dany, then Jon), but this season she's worn out her welcome. She's the weakest actor in the show for me. She doesn't come across queenly when she talks of the things she wants, etc., but as a whining, petulant child and I never saw Dany as that. Dany has a quiet strength, an inner steel and I love her ... in the books. I don't love the Dany in the show. And, sadly, the wandering, meandering feel of her story [Quick last book spoiler] which didn't feel that way for me until this book! Ugh! If the show continues to make changes from the book, changing up Dany's story that happens in the last book would certainly work for me. makes me not exactly excited about her scenes.
Also a problem for me is the the casting of Melisandre. I don't deny that the actress is wonderful because she is, she just doesn't feel like Melsandre for me. Ah well. Overall, though the acting is excellent and keeps things swimming along beautifully.
So, yeah, there you go. If anyone has any specific questions about characters, actors, arcs, plots, book, show, stuff, feel free to ask in comments. :)
Phew! I wanted to get this out before the new episode tonight.