Elegant Themes - Simple, yet beautiful WordPress themes with easy to use implementation and support.
ThemeGrill - ThemeGrill is an online marketplace that develops and sells WordPress themes and plugins that you can buy to create professional websites for businesses, magazines, and blogs.
ThemeFuse - ThemeFuse is a store that provides high-quality designed WordPress themes to let you stand apart from the crowd.
PremiumPress - wordpress themes for business
Rockettheme.com - RocketTheme creates industry leading premium Joomla Templates, WordPress Themes, Magento Templates...
WooCommerce - A freely available eCommerce plugin that enables shop facilities on your WordPress website. Functionality enabling extensions & beautiful themes available.