FileBrowse

FileBrowse is a new, easy-to-use file/media browser for Mac OS X with many unique features, such as 3D icons/thumbnails, large in-context previews, and powerful grouping and sorting.

FileBrowse can show thumbnails for many file types, even on Mac OS X 10.4. Folder icons show the items inside! So you don't always have to open a folder to see its contents.
As you can see, FileBrowse uses 3D icons. These are not pre-generated drawings like standard Finder icons, but instead are rendered in real-time in glorious 3D, using the power of OpenGL hardware acceleration, with lifelike, soft shadows, perfect anti-aliasing (no jagged edges), and realistic perspective (with the vanishing point in the center of the screen). When you run FileBrowse, you’ll notice that the icons appear to float on your display! (This effect is stronger when you try FileBrowse on your computer than it is in the screenshots on this page, because FileBrowse will calculate the correct perspective for each icon depending on its position on the screen, which changes when you scroll or drag the window, for example.) The icons/thumbnails shown on this page are non-enhanced and look exactly the way they look in FileBrowse.