$re = '/,(?!")(?=.*")/m';
$str = '945,"Hey You, Pikachu!",N64,1998,Simulation,Nintendo,0.83,0.06,0.93,0,1.83
1835,"The Game (XBox 360, PS2, PS3, PC Versions)",PS2,2007,Action,Activision,0.63,0.37,0,0.11,1.11';
$subst = "";
$result = preg_replace($re, $subst, $str);
echo "The result of the substitution is ".$result;
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for PHP, please visit: http://php.net/manual/en/ref.pcre.php