Earlier today the fine folks at Brookings announced that they have made all past and current issues of Brookings Papers on Economic Activity free. You can find them here.
Some specific papers that readers of this blog might enjoy (all from the Spring 2009 volume):
Jim Hamilton on the “Causes and Consequences of the Oil Shock of 2007-2008”
Christina D. Romer and David H. Romer on “Do Tax Cuts Starve the Beast? The Effects of Tax Changes on Government Spending”
Phill Swagel on “The Financial Crisis: An Inside View“