There are thousands of great blogs out there which I haven't come across, but for my money Dave Kirkman's 48 Files is the second best blog in human history. (Ok maybe third - it goes, A New Name, daylight, then The 48 Files. But third is still pretty good.)
Just check out these from the last week alone...
How to consider faithful followers of another religion? A brilliant analogy
Why university years are so fruitful for the gospel. (No, not because there's a magic receptivity-window of four years in the life of the middle class!)
What is faith? Faith is receiving the gift. NOT a condition for receiving the gift.
The outgoingness of God's glory. Father to Son to church and out.
And many, many more...