Times online, UK published a list of 50 best business blogs. Corporate and anti-corporate alike. The list include blogs which made companies review policies after Campaigns by bloggers (especially Jeff javirs war against Dell and a blog set up by a disgruntled Land Rover owner)
No clue what methodology Times followed or which blog is the best blog, the list is basically more of US-UK Blogs.
Not in the list but a blog which got lot of attention is a blog written by a small ice cream shop owner in Ireland, Kieran Murphy owner of Murphy’s Ice Cream. He was concerned that he may loose personal touch with customers as he expands his ice cream stores in other cities and decided to blog about ice creams. A recipe idea that Murphy wrote into his blog has ended up creating a whole new market for a range of hot chocolate drinks in Ireland. Murphy’s ice cream blog shows how blogs can be used to build brands with little investment
Also another interesting link which lists 150 top marketing is http://adage.com/power150/