I've been meaning to write something just like this, so I whipped something up this morning.

I think it's going to need some sort of hammer protection, because as it is now you can just sit there and hit refresh to make the counter go up. But other than that it does the trick quite nicely, and you can also use it on non-MT pages also. You can put your IP in to make it ignore your own visits.
So, add a table in your mysql database:
CODE
CREATE TABLE pageviews (
pagename tinytext NOT NULL,
viewcount int(11) NOT NULL default '0'
) TYPE=MyISAM;
And then create a new index template with the script:
CODE
<?
include '/full/path/to/connect/file.php';
$pagename = $REQUEST_URI;
$viewcount = 0;
$query = mysql_query("SELECT * FROM pageviews WHERE (pagename = '$pagename') LIMIT 1");
while($row = mysql_fetch_array($query)) {
$viewcount = $row['viewcount'];
}
if ( $REMOTE_ADDR != '64.xxx.xxx.xx') {
$viewcount = $viewcount+1;
if(mysql_num_rows($query) == 0) {
$insert = mysql_query("INSERT INTO pageviews (pagename, viewcount) VALUES('$pagename', '$viewcount')");
} else {
$update = mysql_query("UPDATE pageviews SET pagename = '$pagename', viewcount = '$viewcount' WHERE pagename = '$pagename'");
}
} // end IP
echo 'viewed: '.$viewcount;
?>
So then you'd include on all the pages you want to count, and then you can do just a regular query to make a list of the most popular.