the impactful free agents (that I can remember):
2006 - Brees, Scott Fujita, Billy Miller, Terrance Copper,
...Deloatch with the TD on Gleason's block
2007 - David Patten, Kendrick Clancy, Dhani Jones
...David and Kaesviharn
2008 - Randall Gay, Bobby McCray
2009 - Darren Sharper, Jabari Greer, Anthony Hargrove, Heath Evans
...was optimistic about Clint Ingram, but he couldn't stay healthy.
2011 - Darren Sproles, John Kasay
yep, terrible acquisitions...McBride and Herring have been disappointing.
2012 - Curtis Lofton, Ben Grubbs, Brodrick Bunkley, David Hawthorne, Chris Chamberlain
Lofton and Grubbs have already had their impacts, but hopefully all these guys will be significant acquisitions from 2012 (putting this FA year up there with '09).
...sprinkle in a little of #25-R. Bush