I would humbly submit 95's 'carwash intake' for your consideration in this thread. Our 2014 over-the-bumper design is an evolution of our 2012 over-the-bumper intake.
The key features are shaping the arms at a radius slightly larger than the ball so that the robot can turn sideways onto a ball and collect it instead of knocking it away. The cut-out also allows us to pick up the ball completely off-center, making our effective pickup width a little bit wider than the 29in width of our robot. Using drawer liner as the 'carwash flaps' allows us to have a very high linear speed on the OD of the intake, but will collapse down and allow us to effectively (but not overly) pinch a large variance in ball OD. When the roller starts to pinch the ball and load up/collapse, the smaller OD gives the intake more torque with which to pull the ball in/out. They are also very easy to package because the flaps collapse down, and it is very easy to pass the ball from one side's intake to the other. Being collapsible also means that they are very damage tolerant. Along those lines the whole intake was deployed with relatively low-force cylinders which allows a defender (or a wall, or a low goal) to push the intake back into our robot without damaging either us or the defender.
https://www.flickr.com/photos/supato...57643219020225