California Academy of Sciences
It's hard to believe, but differently colored buttons replacing monochrome gray rectangles can make a big difference. The small, obvious changes can be huge, especially in making a content entry system user-friendly.
Our work for this site was on the back end, making editing content a friendlier proposition. Besides buttons, we split up long, visually taxing lists into sections and added a sidebar. (Imagine a Wikipedia as a block of text without pictures or headings—painful, right?)
We also enabled a feature to preview changes while keeping existing content live, enabling collaboration in working alternate versions without interrupting the site's usability.
These small tweaks can be all a site needs to become more functional and easier to use—the pinch of salt in your pasta water. That pinch is just a few grains of sodium chloride, but try pasta without them and you'll see the difference.