Interbrand is a marketing consultancy that values well-known corporate brands. In its latest survey: 1. It claims Coca-Cola remains the world's top brand, valued at $68 billion, though down slightly from the previous year. 2. Car companies and luxury brands like watchmakers saw above average declines in brand value due to the recession. 3. Brands associated with cheaper products like McDonald's and Kellogg's saw their value rise relative to others.