Mine, of course. But I don't have any maps. Just history and etc.
I would also highly recommend John Scott's Virtual Fantasy: Forgotten Realms Index. It is an extremely ambitious project designed to link to and reference all available Realmslore (both published and web-based, "canon" and fan-made).
I have always been impressed with <a href="http://www.gemofthenorth.org/">Project Silverymoon</a>, which offers a wealth of info on Silverymoon and its environs. Top-notch stuff, too.
It used to be a draw between www.RealmSpeak.com and AJA's site. Now RealmSpeak is down so I second AJA's recommendation of his own site. He's one of relatively few people, TSR/WotC authors included, who really get the Realms feel right.