User-generated content communities have been around for years. In fact, many top websites allow their loyal readers to submit their own content. If you are planning to start your own user-generated content site, you may want to give these themes a look:
Uploader: a media sharing theme with frontend upload functionality. You do have the option to limit the number of file uploads per user.
Katla: allows users to submit content and vote on other stories. Your visitors can login/register from over 20 social sites. It offers Reddit-like post sorting.
SocialChef: a responsive theme with BuddyPress and bbPress integration. It is responsive and ready to be translated. Front-end recipe submissions are supported.
Serpent: a social community theme with keyboard navigation, Facebook commenting, social media sharing. Your visitors will be able to submit images and videos in their posts.
Have you found better themes for user-generated content sites? Please share them here.