GPLDL - 1066 GPL-licensed WordPress themes & plugins for free
Theme Forest - The #1 marketplace for premium website templates, including themes for WordPress, Magento, Drupal, Joomla, and more. Create a website, fast.
LyrWP - WordPress themes / plugins / services curated.
ThemeFuse - ThemeFuse is a store that provides high-quality designed WordPress themes to let you stand apart from the crowd.
Blocksy - A lightningfast, innovative and supercharged WordPress theme
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.