Australia: Porn Featuring Small Breasts

While the law doesn't outright ban porn featuring small breasts, the ABC has the right to ban all adult films that depict a woman as being under 18. While this idea sounds fine in theory, the group has actively rejected some films based solely on the breast size of the actresses involved.
China: Game Consoles

Greece: Video Games

Fortunately, after receiving pressure from the EU and video gamers everywhere, the law was found to be unconstitutional by the end of the year.
China: Avatar in 2D

Russia: Emo Clothing

The government went so far as to dub the style “a threat to national stability” before banning people from wearing emo clothing to public schools or government buildings. Don't worry sullen teens of Russia, you can still listen to all the forlorn emo music you want, you just can't dress like you listen to it.
China: Reincarnation Without Prior Consent

Iran: “Western” Hair Cuts

Saudi Arabia: Valentine's Day

Denmark: Ovaltine and Marmite

Update: According to the Denmark Embassy in England, it's not illegal to sell or possess Marmite, just to advertise it.
Denmark: Most Baby Names

China: Jasmine
