I'm not a huge fantasy fan but this series has me hooked. After hearing all the accolades for the show I thought I'd check out the novels. I expected something along what I dislike about most fantasy, a kind of high serious comic book mentality with buxom barely clad ladies and muscle-rippled swordsmen, long-bearded wizards with runestones and ludicrous spells, fantastical creatures that defy a naturalistic universe, and all manner of juvenile silliness. You know, pulpy genre writing.
Instead, Martin has crafted a really well thought out alternate world with some wisps of the fantastical, but mostly it is a tale of dynastic grudges, political maneuvering, and palace intrigues. The characters are interesting (especially the dwarf Tyrion), the plotting is complex (there are factions within factions within factions), and the canvas is broad.
It's somewhere in the space of 4,000 pages, so it's clearly a long-haul, but Martin keeps it from ever being a slog.