lots of suggestions, seems that ethiopian and air india are popular choices, and some controversy over Continental and AA.
it was also pointed out that most airlines these days are going for all white liveries. I strongly disagree. The all white was a 90's thing, over the past 5 years or so, airlines have gone for colour, such as Vietnam, China Airlines, Saudi Arabian, US Airways, United, BA, Austrian even added a cheatline. There are, understandably a few exceptions, most notably, Delta and Swiss of late, but airlines went crazy in the 90's, now a colourful, strong corporate branding is more what the airlines go for.