What are the best and worst business blogs you've seen?

What are the best and worst business blogs you've seen?

I’m on a panel tomorrow at a Motor Industry Public Affairs Association event about blogging.
I’m on the lookout for some examples of business blogging and its best and at its worst.
So what’s the best business blog you’ve seen? And why is it so good?
And at the other end of the scale what’s the most disappointing business or corporate blog you’ve seen?
I appreciate any examples readers of this blog can let me have – open source presentation writing in action!

About SIMON

I work with technology-centric businesses as an interim Chief Operating Officer (COO), consultant and advisor. I created the B3 framework® for scaling technology businesses and I write a newsletter called Build for leaders who are building brilliant companies.