There are many Armory sites out there, since Blizzard had the foresight to put the Armory data in XML so anyone who wanted to could use it in alternate presentations. 3D Armory is a new Armory site, just released into public beta. As you might have guessed, the focus of the site is on loading your character's data and displaying a 3D model of your toon; for instance, at top right you can see my death knight and how his gear looks in-game (yes, I'm still wearing my heirloom shoulders).
It does what it sets out to do, and does it pretty well: just select "eu" or "us" from the popup at the top of the page, type in your realm and character name, and hit go. Points off for having cryptic icons for all the functionality with only tooltips to indicate what they might do - I'm a big fan of obvious UI over flashy-looking UI.