Bruce Murray Space Image Library
Asteroids and comets visited by spacecraft as of August 2014, in color, excepting Vesta

The "click to enlarge" version has a resolution of 100 meters per pixel. Here is a version at 20 meters per pixel.
Bruce Murray Space Image Library
The "click to enlarge" version has a resolution of 100 meters per pixel. Here is a version at 20 meters per pixel.