Stanford has released a dataset intended to be used to improve the state of the art in x-ray image classification.
Download it here and eter your own submission to the challenge: https://stanfordmlgroup.github.io/competitions/mura/
Deep Drive Dataset available
The large dataset for teaching your algorithms to drive can be downloaded from http://bdd-data.berkeley.edu/.
It contains over 100,000 HD video sequences, that make up over a thousand hours of footage. The data contains over 100 000 annotated images for object detection for bus, traffic light, traffic sign, person, bike, truck, motor, car, train, and rider. Alos segmentation, drivable area, lane markings etc.
I love how data is released to the public for the greater good.