I'd say Minnesota and the midwest states take it for worst roads, especially in the city areas. The freeze/thaw and snowplows decimate our roads every winter.
No chance! MN and WI are so proactive about road maintenance that we get pretty good roads despite the extra hassles caused by cold weather. I've spent a bit of time in Los Angeles and Hawaii, and those roads are easily in worse condition than the roads of Minnesota and Wisconsin.
I will confirm this. Just had to replace part of my exhaust a few weeks ago because I bottomed out hitting a pot hole at night I couldn't see until too late.