Peter Dinklage as Tyrion Lannister. Sean Bean as Ned Stark was almost met with as much praise, and most of the other casting is also loved by fans. Ian McNeice as Illyrio (although he didn't make it past the original pilot) and Rory McCann as The Hound were two where the fans rejoiced but the characters weren't as important.
Harry Lloyd being cast as Viserys also caused a bit of squee for those who saw him being awesomely insane and creepy as a possessed Jerk Jock in Doctor Who.
Charles Dance, yet another fan favorite, cast as Tywin Lannister.
And then the second teaser and behind-the-scenes peek happened. Oh god. Early reactions are comparable to that original Fellowship-over-the-ridge teaser for the Lord of the Rings movies.
Fans of The Wire rejoice! Petyr "Littlefinger" Baelish will be played by Aidan Gillen, who played Tommy Carcetti in season three onwards. The man knows how to do despicable-yet-convincing!
A half-ATFR for the announcement that Dominic West had turned down a role which, based on the interview, was almost certainly Mance Rayder. It sucked that he turned it down, but it showed what caliber of actor that they were looking for.
And, after the release of the Artisans video with Maisie Williams, the young actress set to play Arya, the fandom rejoiced yet again.
The announcment that Natalie Dormer has been cast as as Margaery Tyrell elicited much rejoicing from the fandom.
Gwendoline Christie was a longtime fan favourite for the role of Brienne, so when she was announced as having been cast in the role it made a large number of people very happy.
The news that Shireen Baratheon, Selyse Baratheon, Beric Dondarrion (re-cast), Thoros of Myr, Olenna Redwyne aka the Queen of Thorns, Mance Rayder, Tormund Giantsbane, Meera and Jojen Reed (Ellie Kendrick and Thomas Brodie-Sangster respectively), and of course Ser Brynden Tully aka the BLACKFISH will be cast for Season 3.
And once the actual casting was revealed, the fans were particularly excited for Dame DianaRigg as Olenna.
Tyrion using a battle-axe and finally being seen fighting in battle.
Not to mention the (in)famous chain of hands that the Hand of the King wears was shown.
Set◊ photos◊ confirming that the Tully seat Riverrun will finally appear after 2 seasons of not appearing. The crew has really gone all out designing it.
Although it has not yet been confirmed that he will be playing Ramsay Bolton, it is confirmed that Iwan Rheon of Misfits will be in the cast next season, and the fandom is more or less convinced that he will be Ramsay. Opinions are divided, between the "squee" response, and a fear that Rheon's good looks and acting will make Ramsay Bolton too sympathetic.
Sharp-eyed fans have noticed that Iwan Rheon's facial expressions are very similar to those of Michael McElhatton, who plays Ramsay's father Roose. And we can always count on the special effects wizards to make Iwan look extra creepy.
Also, all the hints being dropped by the series so far as to "The Boy's" true identity and nature are pure foreshadowing porn to those who know whats coming.
Ciaran Hinds, AKA Gaius Julius Caesar, finally filling in the role of Mance Rayder, one of the most speculated parts.
Martin confirming that the bear pit scene was in (even though they had to shoot it in Los Angeles for logistical constraints), and a few weeks later, some very clear implication that giants would also appear. Almost everyone was assuming that both had been cut to lower costs!