Rocket Theme
Rockettheme is the most popular joomla templates club. we have a large resource of free and professional joomla templates, extensions and tutorials.
http://www.rockettheme.com/
The Template Shop
Here you can buy profesional designed joomla/mambo templates
http://www.the-template-shop.com/
Pixelsparadise
Pixelsparadise
http://www.pixelsparadise.com/
MamboShop
Mamboshop sells website templates for the content management systems typo3, joomla and mambo. the prices are moderate and the designs come with many extras.
http://www.mamboshop.com/home.php?cat=250
Joomlart
Joomlart.com is one of the most popular joomla templates club. we have a large resource of free and professional mambo joomla templates, menus, modules, components and mambo joomla tutorial.
http://www.joomlart.com/
JoomlaMarket
Demonstration of all available joomlamarket templates
http://demo.joomlamarket.de/