How much is the little TM next to "Coca-Cola" worth? How about more than US$15 billion per year? According to this ACNeilsen report, there are 43 worldwide billion-dollar brands, and Coke tops them all, followed by Marlboro. The complete list, by value:
Benson & Hedges
It's interesting that the top brands are sodas, cigarettes, and beers. Make sure to note that the study only includes brands that have a presence all around the world.
Oligopoly Watch has a table with more information, so rather than recreate it I'll just point you there.