If you have a weekend to spare:
http://www.publicintegrity.org/investigations/broken_government/articles/full_list/
http://www.publicintegrity.org/investigations/broken_government/articles/full_list/
Raised the IQ in the white house by 50 points.
Bush's biggest failure was allowing the Iraqi army to be disbanded immediately following the invasion. This sent hundreds of thousands of trained fighters back home unemployed, disenchanted, and easily recruited by insurgency groups. That single mistake led to the long bloody occupation that followed.