Nearly a century and a half ago, the book 507 Mechanical Movements cataloged a wide array of mechanical movements. The book (which has long been in the public domain), has been reprinted more recently and is one of my favorites on the bookshelf. There is now even a website which demonstrate some of those mechanisms with 2D animations.
Thanks to AutoCAD Inventor, there is now a modern catalog gathered in this amazing YouTube collection of animated 3D-models, thanks to retired engineer Mr. Nguyen Duc Thang.
According to Mr. Thang's about page, there is a staggering collection of 2,100 mechanism videos that he has amassed and cataloged! What a gold mine!
This collection should keep you busy for a few hours, and are sure to to come in handy when looking for inspiration for your own new mechanisms!
Hat Tip: http://hackaday.com/2016/02/29/2100-mechanical-mechanisms/