The Business Week/Interbrand 2009 Best Global Brands Study showed Google had moved from the position of 10th biggest brand in the world to number seven in the chart, after the value of its brand rose by 25% to almost £40bn.
Amazon rose from 58 in 2008 to 43 this year, with Interbrand estimating the worth of its brand had risen by 22% to £7.9bn.
By contrast, Yahoo!, which is seen by many to have lost its way somewhat, saw the value of its brand fall by 7% to £5.1bn. It slipped down a place in the rankings to number 64.
Adobe, maker of the now ubiquitous Flash software appeared in the list for the first time, with Interbrand ranking it at number 95.
Microsoft remains the third biggest brand in the world, but saw a decline in its worth of 4% to £56.6bn. Only Coca-Cola and IBM are ranked above Microsoft.