Canadian media is even more concentrated than the US market believe it or not. CBC, CanWest Global, and CTV dominate the landscape tv and radio wise. CanWest dominates the print media. But in the end they are all pretty much trustworthy. CanWest owners are open and honest that they side with conservative ideals but are still read and watched by a majority percentage of Canadians - though they are having financial difficulties as of late.
CBC being the national public broadcaster produces material the others won't/don't. Their documentary work, public affairs programs and International coverage is second to none in Canada imo. For local news CanWest is fine.