The cobblers' kids DO have shoes
The old expression "The cobbler's kids have no shoes" holds true for many businesses and their websites. Often marketing agencies are terrible at marketing themselves. Great shops have websites where you can't shop. Information technology companies are often lacking information and using old technology.
But here are a few examples of web design companies whose sites serve as an endorsement of the quality of their work. Their kids are walking around in some spiffy shoes.
Digital Kick - be sure to click around and explore.
AgencyNet - very creative design. Navigating can be a little confusing.
Avenue A / Razorfish - very clean and clear.
352 Media - integrates video onto their homepage. Also see MindComet.
New City Media - attractive design which highlights their portfolio.
Red Clay - beautiful imagery.
Ironworks - a shameless plug for my employer.