Both Intel Atom carriers have a nice sleek design with a glossy case and nicely rounded curves, except for the Asus EEE PC which has sharp edges, a characteristic of the Asus design style, and the feel of its plastic case is somewhat rough. The MSI has a nice sleek logo centered on the top different from their original. The Acer also has great design with little details of orange hinges on both sides to make the whole thing look fancier. They all come in more different colors(white, blue, pink, black..).
Although design is more of a personal thing, the logo placement, the stylish power and WiFi buttons, and orange hinges on the sides makes me want to just take a bite of the Aspire One.
1st: Acer Aspire One
2nd: MSI Wind U100
3rd: Asus Eee PC