A very pretty natural food establishment. I'm not crazy about the kind of cramped layout, which really is inconvenient, considering how many people are always there. Still, it's usually a nice experience.
They have some of the best produce available in Madison (and also the most expensive). When I made Beef Wellington one day, they were the only place that had truly gorgeous-looking cuts of Fillet Mignon (again, expensive).
The really nice thing about Whole Foods is the "Whole Foods brand." This allows you to buy things at a reasonable price. :) I also am a big fan of their take-out/deli foods. Mmmm, good...