Here is yet another example. The mayor of Trenton, NJ -- the state capital -- has been arrested for corruption.
http://www.cnn.com/2012/09/10/justic...ted/index.html
I would love to say that this is an isolated incident, but it's not.
Bribery is extremely common in city government. If your city has inexplicably changed to another company for certain utilities (and ignores complaints), or if they seem married to some particular developer to do all of their work, there is almost surely bribery involved.
The problem is that, unlike at the state and federal level, there aren't enough people watching what's going on with city politics and the expenditures of city money, so this corruption runs rampant.
Then, of course, there are large city governments like Chicago where corruption is a way of life, and people have just come to accept it.