I liked the first image from The Animator's Survival Guide as it shows the squash and stretch of the face and how dynamic the shape of the face will need to be.
This image, from the Art of Wall-E, shows the facial expression with regards to the movement of the character. I will need to think about what my character will be doing and their whole body demenour when creating the blendshapes.
Also, it may not be a completely human character that I am going to rig. I really like these images from the Art of Robots, showing how much personality and expression will be coming from robotic creatures.
Similarly, the Art of Cars shows their expressions. It is interesting looking at these books, as even though these are from CG films, they still plan all of the expressions out by drawing them. I think I need to do more planning.
The cars do have the really big eyes which is the focus of their expressions. It is really interesting to see how they tilt the front of the bonnet to create expressions too.
Going back to traditional, this photograph from Timing for Animation shows possible expressions. The main emotions that seem to appear in my research are sadness, extreme sadness, smile/happiness, anger and shock. Obviously not pushing these to the extremes can make all kinds of emotions inbetween.
I found these videos on youtube, it has been really interesting to look at research into facial expressions, not just from an animation point of view but scientifically aswell.