NY Mag’s Vulture website has a “Number 1: Game of Thrones (and A Song of Ice and Fire) fans!
Is it true? I can’t speak for all the other very worthy fandoms, but ASoIaF certainly has a terrific fanbase. There’s shout-outs to Westeros.org, the Brotherhwood without Banners, Winter is Coming, and more—they’ve done their research, to say the least.
(Thanks to levifilm for pointing this list out!)