Several new additions to the links on the left that I recommend:
Deltoid is an Australian blog that attacks bad science, mostly regarding authors who make up studies to prove gun control is bad or that climate change doesn't exist. Most doggedly persistent analysis I've seen, and he beats the heck out of any of his subjects when they fight back. This site exposed a prominent gun control opponent, John Lott, as a liar.
Brad DeLong is a (liberal) UC Berkeley economist writing about current economic issues. I find him especially interesting to read because I don't think he's taken a position yet on Social Security privatization, but has many bad things to say about the Bush administration's approach so far.
Fafblog is a group blog authored by Fafnir, Giblets, and The Medium Lobster. Someone with the strange name of Chris is occasionally mentioned. Besides recounting their various adventures, they enthusiastically "advocate" conservative positions by taking those positions to their logical extremes.
All worth taking a look.