D7000 is the best of these options. When you compare the sensors, the D7000 comes out well ahead of the 7D. I suspect the update to the 7D will be aiming to score as well as the D7000. http://www.dxomark.com/index.php/en/Camera-Sensor/Compare-sensors/%28appareil1%29/680|0/%28appareil2%29/619|0/%28onglet%29/0/%28brand%29/Nikon/%28brand2%29/Canon
Unfortunately sensor capability is only one part of the equation when choosing a camera.