They are not specifically bloggers, but their regular commentary has proved invaluable to me.
Editor's Note: I have always found Barton Biggs' writing to be very insightful. I can also recommend his books, especially HedgeHogging. His strategic investment and asset management experience is exceptional and if he speaks - or writes - we should all pay attention.
Stephen Roach is also incredibly experienced, but is more pessimistic about the economic climate. Of course, writing this in late 2009, and seeing where the world economy has gone this year, his gloomy commentary could be seen as entirely justified!