This snippet resets the node read count to zero.

UPDATE `node_counter` SET `totalcount` = '0'

Of course if your database tables have a prefix, you will need to change the snippet along the following lines ...

UPDATE `drupal_node_counter` SET `totalcount` = '0'

This is useful if you need to clear node read statistics during the development phase of a website and want a zero count at launch the the rest of the world.

For those who aren't savvy in MySQL, one can also disable and uninstall the statistics.module and reinstall statistics.module to reset counts to 0.