Brilliant site, thanks for the reference
I would also like to suggest GameTextures.com & Arroway Textures. I use to own a CGTextures Corporate Membership due to wanting IP Whitelisting but did not renew after the year was up. As for GameTextures.com, while good it did not get enough use from us to merit continuing our old Commercial monthly subscription and while Arroway Textures has brilliant texture quality + resolutions going upwards of 20k by 15k, the price might might scare most off (I personally own the All-In-One Bundle) yet I would still highly recommend a 1-time purchase of one of their bundles for those doing photo real games, arch viz and film/CGI.
NOTE: I’ve heard a lot of good things from people regarding recent changes that GameTextures.com has made to their collection, including a change of pricing structure and PBR game-ready textures being introduced, so I might consider renewing our license with them at some point in the future.