Freebiesbug - Collection of the best free web design resources.
UI Movement - The best UI design inspiration, daily
Design Hunt - Curated design inspiration for everyone
Freepik - More than a million free vectors, PSD, photos and free icons. Exclusive freebies and all graphic resources that you need for your projects
UI Jar - Hand-picked design inspiration for your real life projects
Facebook Design - Resources for Designers from the Facebook Design team