bl.ocks.org is a simple viewer for code examples hosted on GitHub Gist. Its run by Mike Bostock and its the primary source of D3 examples online. Many examples are posted daily on there, however they aren't easy to find unless you use bl.ocksplorer.org. Type any d3 API call into the searchbar and quickly see the blocks (or gists) that use it.
The reason I got into digital data visualisation was to build interactive sites which capture the imagination and either tell the narrative behind the data or let you find your own stories through intuitive tools. I'm not quite there yet, but here are a couple of examples that demonstrate what I mean.
As you can see from the example above, studios that specialise in data visualisation and have the capacity to employ data viz designers and developers have the capability to produce fantastic work. Here are a few whose work I really admire: