2011's two most popular non-music channels on Youtube both belong to game-related companies: trailer and original video content community Machinima, and gaming news site IGN.
Machinima, which shares "trailers, gameplay, montages, and original scenes in video games" on its YouTube channel page, recently revealed that its videos saw a total of more than a billion views in November 2011.
Since Machinima created its YouTube account in 2006, the channel page has seen over 119 billion views, while its 450,000+ uploaded clips have brought in more than 2.9 trillion views.
The IGN entertainment channel shares video reviews, news, and trailers for games, and was the second most-watched channel this year. It has seen 33.2 billion channel page views and 1.4 trillion video views since 2006.
These two channels beat out other popular channels in the comedy, musical comedy, and how/to advice categories.