The Iron Throne as described in the novels, officially endorsed by GRRM on his blog as the most accurate artistic representation thus far. By artist Marc Simonetti.
"The way the throne is described in the books… HUGE, hulking, black and twisted, with the steep iron stairs in front, the high seat from which the king looks DOWN on everyone in the court… my throne is a hunched beast looming over the throne room, ugly and assymetric.The HBO throne is none of those things." — George R.R. Martin.
By comparison the chair in the HBO series is a comfy cushioned couch… this is terrifying.