As a British person, you also associate different stereotypes with different accents, so as has already been said, you are going to instantly think someone with an RP (Lannister) accent is more posh and higher up the social scale than the "Northern" accents you get from the Starks. Amongst the Lannister's, Cersei and Tywin's are the only true southern/RP accents (Tywin's is the more actorly traditional RP, whereas Cersei's is a southern accent you would hear on the street), Jaime's is very good with just the very rare stray word, while to my ears Tyrion sounds like he is pronouncing every single word too precisely to be truly authentic. I mean, I love Peter Dinklage but you can tell (in a way you can't with Jaime) that he's putting the accent on. As someone else has said, the Stark children's accents make no sense. While Robb and Jon do their best to copy Sean Bean's Sheffield accent, Sansa and Bran sound like they are from the Home Counties, while Arya has an ever so slight West Country accent. In my head, I put this down to the younger children being closer to their "southern" mother, who does a very good Southern English accent even though Michelle Fairley is from Northern Island. Another set of interesting characters are Robert, Stannis and Renly, who for brothers have wildly different accents. Robert also has a Yorkshire accent, though a different one from Sean Bean. Sean Bean's is a Sheffield accent, and I believe Mark Addy (who plays Robert) is from York, but even though the cities are only fifty miles away from each other, you can tell they are from different places. So, even though I though "they were both raised by Jon Arryn", their accents are different enough to really make no sense. Stannis and Renly have quite non-descript southern accents, which I never thought made sense with Robert's York accent. Again, I think this was done to contrast the rougher, northern houses with the more gentile southern houses, but in this case they weren't consistent. Not that it spoiled anything for me, it's just if you think about it, it makes no sense! The only other interesting accent I think in the show is Littlefinger's - it is not an accent I have ever heard! I know Aidan Gillen is Irish, and it definitely has an Irish lilt to it, but sometimes it comes out sounding vaguely Welsh, and sometimes southern, and sometimes northern. I mean, I think he's great as Littlefinger, and I put it down to "oh, he's from some really small town somewhere on the Fingers", but it does sometimes sound quite strange! Just a random fact, the only Welshman on the show is (I believe) Iwan Rheon who plays Ramsay, who does a very good southern accent (even though he's meant to be from the north!) I believe that Iwan's mother tongue is actually Welsh, and that he only learnt English later. You can find clips of him interviewing in Welsh on the internet!