My six go to sites when I am looking for design inspiration.
Twitter Bootstrap Expo
I love Bootstrap, I use it for every project. The expo is a collection of websites built with Bootstrap showcasing how others have utilized the framework.
Awwwards is a collection of websites that you can vote on. Criteria include; design, creativity, usability, and content.
Site Inspire is a massive collection of websites updated everyday. Careful with this one, time stands still when you are on it.
Dribble, the show and tell for designers. This gives individuals a platform to show the world what they are working on.
Much like Dribble, a place you can show the world what you are working on and collaborate with others.
Known for the UI kits, but I enjoy reading their blog. They post a lot about trends and show off some pretty cool websites. I always find myself leaving the site with a new idea.