The BBC is presenting a series on world-wide corruption via its radio program, but it also has an interactive website here. On this link you will find a corruption index. Click on the percentage legend to the left of the map and see what percent of those responding to the survey by Transparency International said they paid a bribe for favors.
Surprise, surprise … political parties, police, judiciary, legislative bodies and appointed officials are the most corrupt, in that order (On the right side of the above map is a vertical link, 'Which Public Body Is Seen As The Most Corrupt'). Once on that map you can click on the categories. For my Australian friends the Media pops up as the most corrupt.
Transparency International Spells It Out: Politicians Are The Most Corrupt