Stephen Shields has a list of the Most Legitimately Influential Blogs for the North American Church :

• Scot McKnight
• Andrew Jones (yes, I'm aware he's not in North America)
  
• Justin Taylor
• Rick Meigs
• Ted Olsen

emergesque readers added:

• Mark D. Roberts
• Ben Witherington
• Hugh Hewitt
• Jamie Arpin-Ricci
• Jordon Cooper
• Al Mohler
• Out of Ur
• Michael Spencer
• John Smulo
• Missional Apologetics

These are blogs well worth checking out. I track they all through my feeds on Bloglines.