It's hard to single out the most inspirational thing on Ravelry, but one of the best, knowlegable, and enthusiastic groups on there is the Socks that RAWK! group. Every quarter, they host a KAL of two sock patterns. Each member is encouraged to use a different colorway of Socks that Rock in order to showcase the amazing diversity of the yarn. It's a fabulous group, and I've gotten lost for hours looking at the photos.
For the first time, I'm participating in the quarter's KAL for the Edwardian Boating Socks. Mine are in the Flower Power colorway. I just cast on yesterday and can't stop knitting!