Garfield daily strips all till the end of 2013.
All in jpg format zipped year by year for your convenience. 	

If you want to download it yourselves here is a PHP script I used to do it: 

<?

/* The initial parameters */
// Source URL pattern
$sourceURLOriginal = "http://garfield.com/uploads/strips/{x}.jpg";
// Destination folder
$destinationFolder = ".";
// Destination file name pattern
$destinationFileNameOriginal = "{x}.jpg";
// Start number
$start = 1;
// End number
$end = 15000;
// start date
date_default_timezone_set ('UTC');
$d = strtotime ("Today");
// From start to end
for ($i=$start; $i<=$end; $i++) {

    // Replace source URL parameter with number
    $sourceURL = str_replace("{x}", date("Y-m-d", $d), $sourceURLOriginal);
    // Destination file name
    $destinationFile = $destinationFolder . "/" . 
        str_replace("{x}", date("Y-m-d", $d), $destinationFileNameOriginal);
    // Read from URL, write to file
        file_put_contents($destinationFile, 
          file_get_contents($sourceURL)
        );
    // change date
        $d = strtotime ("-1 day",$d);
    // Output progress
    echo "File #$i completen";
}

?>