Silhouette based character design.
After learning how Valve designed the models for Team Fortress 2, I had a go at this.
The philosophy behind it is that, in a frantic multiplayer shooter like TF2, it is important to know what class you are fighting simply from a quick glance.
Valve therefore designed their characters in shadow - if it was obvious which class was attacking from just the outline, then it was approved.
So I went to work creating something similar, with a good degree of success I feel.