The print ads for the electric retailer, recognised at Campaign's Big Awards last year, were described as "a clear winner" on the international stage in the report.
The results of The Gunn Report 2010 were announced at the IAA business lunch at The Mandarin Oriental, London.
Ian Barber, director of communications for the Advertising Association, said: "The Gunn Report is an important industry Bellwether and demonstrates the value of the media creativity industry to the global economy.
"Fostering healthy competition between agencies on an international level serves to raise the game and encourages the industry to produce creative work of an increasingly high standard."
The US and UK were once again ranked one and two respectively in the countries table. Turkey was the only new country to join the top 25 in 2010.
BBDO was revealed as The Gunn Report's Network of the Year for the fifth consecutive year, while Brazil's AlmapBBDO (Sao Paulo) scooped Agency of the Year. Advertiser of the year was Volkswagen.
Top honours for Digital Agency was shared by two Swedish agencies – DDB Stockholm and Forsman & Bodenfors (Gothenburg).