Collegiate Christian A Cappella (CCAC) is a loose organization of Christian a cappella groups in colleges across the country. The site has existed since the early days of the web due to the Internet savvy of its founders. When I joined the organization a couple of years later, it was in need of some updating to match then-modern standards for web design.
However, there was a hand-built content management system in place for part of the site (in Perl), and discussions about design inevitably strayed into discussions about how best to replace the programming. It took about seven years for us to finally put a new face on things (the Perl backend is still there, for now).
I stitched the stained glass window set together more than a year ago, hoping to find a suitable home for it. CCAC was a great place to use it, representing the diversity of geography and style found in its member organizations.
This is as far as a hand-built XML and XSLT content system will take me, however. The current page, last modified date, navigation highlights, and feature inclusion are all done through XML; it's stretching its limits. The next big site (if there is one) is going to need something more.