Science Fiction Weekly stated in 2000 that "few would dispute that Martin's most monumental achievement to date has been the groundbreaking A Song of Ice and Firehistorical fantasy series", for which reviews have been "orders of magnitude better" than for his previous works, as Martin described to The New Yorker. In 2007, Weird Tales magazine described the series as a "superb fantasy saga" that "raised Martin to a whole new level of success". Shortly before the release of A Dance with Dragons in 2011, Bill Sheehan of The Washington Post was sure that "no work of fantasy has generated such anticipation since Harry Potter's final duel with Voldemort", and Ethan Sacks of Daily News saw the series turning Martin into a darling of literary critics as well as mainstream readers, which was "rare for a fantasy genre that's often dismissed as garbage not fit to line the bottom of a dragon's cage". Salon.com's Andrew Leonardstated:
The success is all the more remarkable because [the series debuted] without mass market publicity or any kind of buzz in the fantasy/SF scene. George R. R. Martin earned his following the hard way, by word of mouth, by hooking his characters into the psyche of his readers to an extent that most writers of fantasy only dream of.
Publishers Weekly noted in 2000 that "Martin may not rival Tolkien or Robert Jordan, but he ranks with such accomplished medievalists of fantasy as Poul Anderson and Gordon Dickson." After the fourth volume came out in 2005, Time's Lev Grossman considered Martin a "major force for evolution in fantasy" and proclaimed him "the American Tolkien", explaining that, although Martin was "[not] the best known of America's straight-up fantasy writers" at the time and would "never win a Pulitzer or a National Book Award ... his skill as a crafter of narrative exceeds that of almost any literary novelist writing today". As Grossman said in 2011, the phrase American Tolkien"has stuck to [Martin], as it was meant to", being picked up by the media including The New York Times ("He's much better than that"), the New Yorker, Entertainment Weekly("an acclaim that borders on fantasy blasphemy"), The Globe and Mail, and USA Today. Timemagazine named Martin one of the 100 most influential people in the world in 2011, and USA Today named George R.R. Martin their Author of the Year 2011.
According to The Globe and Mail's John Barber, Martin manages simultaneously to master and transcend the genre so that "Critics applaud the depth of his characterizations and lack of cliché in books that are nonetheless replete with dwarves and dragons". Publishers Weekly gave favorable reviews to the first three A Song of Ice and Fire novels at their points of release, saying that A Game of Thrones had "superbly developed characters, accomplished prose and sheer bloody-mindedness", that A Clash of Kings was "notable particularly for the lived-in quality of [their fictional world and] for the comparatively modest role of magic", and that A Storm of Swords was one "of the more rewarding examples of gigantism in contemporary fantasy". However, they found that A Feast For Crows as the fourth installment "sorely misses its other half. The slim pickings here are tasty, but in no way satisfying." Their review for A Dance with Dragonsrepeated points of criticism for the fourth volume, and said that, although "The new volume has a similar feel to Feast", "Martin keeps it fresh by focusing on popular characters [who were] notably absent from the previous book."
According to the Los Angeles Times, "Martin's brilliance in evoking atmosphere through description is an enduring hallmark of his fiction, the settings much more than just props on a painted stage", and the novels captivate readers with "complex storylines, fascinating characters, great dialogue, perfect pacing, and the willingness to kill off even his major characters". CNN remarked that "the story weaves through differing points of view in a skillful mix of observation, narration and well-crafted dialogue that illuminates both character and plot with fascinating style", and David Orr of The New York Times found that "All of his hundreds of characters have grace notes of history and personality that advance a plot line. Every town has an elaborately recalled series of triumphs and troubles." Salon.com's Andrew Leonard "couldn't stop reading Martin because my desire to know what was going to happen combined with my absolute inability to guess what would happen and left me helpless before his sorcery. At the end, I felt shaken and exhausted." The Christian Science Monitoradvised reading the novels with an A Song of Ice and Fire encyclopedia at hand to "catch all the layered, subtle hints and details that [Martin] leaves throughout his books. If you pay attention, you will be rewarded and questions will be answered."
Among the most critical voices were Sam Jordison and Michael Hann, both of The Guardian. Jordison detailed his misgivings about A Game of Thrones in a 2009 review and summarized "It's daft. It's unsophisticated. It's cartoonish. And yet, I couldn't stop reading .... Archaic absurdity aside, Martin's writing is excellent. His dialogue is snappy and frequently funny. His descriptive prose is immediate and atmospheric, especially when it comes to building a sense of deliciously dark foreboding [of the long impending winter]." Hann did not consider the novels to stand out from the general fantasy genre, despite Martin's alterations to fantasy convention, although he rediscovered his childhood's views:
That when things are, on the whole, pretty crappy [in the real world], it's a deep joy to dive headfirst into something so completely immersive, something from which there is no need to surface from hours at a time. And if that immersion involves dragons, magic, wraiths from beyond death, shapeshifting wolves and banished princes, so be it.