GDM has released their list of top developers for 2009. Nintendo is at the top of the list, with Blizzard coming in second.
1. Nintendo (Kyoto studio) (Mario Kart Wii, Wii Fit)
2. Blizzard Entertainment (World Of Warcraft: Wrath of the Lich King)
3. Ubisoft Montreal (Far Cry 2, Prince of Persia)
4. Rockstar North (Grand Theft Auto IV)
5. EA Canada (FIFA Soccer 09, NHL 09)
Check out their list to see the remaining top 20 developers taken from their full list of 50: Gamasutra.com