Of the sites that cover all games
I'd have to say Kotaku. It's gotten so bad, they're just downright trolling these days. Go to kotaku.com and just read any Wii story - here's the first one I saw:
or this one,
The comments are even worse, especially since most Wii owners have left the site due to snobcore trolling from the journalists themselves.
Can you think of a site that hates Wii as much or more than Kotaku?
On the flipside, MTV's multiplayerblog is refreshingly unbiased, professional, and actually makes an attempt to understand Wii.