Theme Forest - The #1 marketplace for premium website templates, including themes for WordPress, Magento, Drupal, Joomla, and more. Create a website, fast.
UI Movement - The best UI design inspiration, daily
GeneratePress - Responsive, easy to use WordPress theme
UI8 - Carefully crafted UI design assets
Elegant Themes - Simple, yet beautiful WordPress themes with easy to use implementation and support.
UI Garage - Specific mobile and web design patterns for your inspiration