In Magento store some times we are required to display most Viewed Products on store’s home page or some other places. To do so we will perform the same as :

first of all we have to create a file in the path  app/code/local/Mage/Catalog/Block/Product/Mostviewed.php with the following code in it :

class Mage_Catalog_Block_Product_Mostviewed extends Mage_Catalog_Block_Product_Abstract{
    public function __construct(){
        parent::__construct();
        $storeId    = Mage::app()->getStore()->getId();
        $products = Mage::getResourceModel('reports/product_collection')
            ->addOrderedQty()
            ->addAttributeToSelect('*')
            ->addAttributeToSelect(array('name', 'price', 'small_image'))
            ->setStoreId($storeId)
            ->addStoreFilter($storeId)
            ->addViewsCount();
        Mage::getSingleton('catalog/product_status')->addVisibleFilterToCollection($products);
        Mage::getSingleton('catalog/product_visibility')->addVisibleInCatalogFilterToCollection($products);
 
        $products->setPageSize(5)->setCurPage(1);
        $this->setProductCollection($products);
    }
}

Secondly,  Create another file in this path app/design/frontend/default/YourTheme/template/catalog/product/mostviewed.phtml with the following code in it. The below code will fetch the most viewed products on the page but we have to call this code in a block. 

<?php if (($_products = $this->getProductCollection()) && $_products->getSize()): ?>
    <div class=" most_viewed">
        <div class="mv_title"><?php echo $this->__('These Products Are Popular Right Now!') ?></div>
        <?php $_collectionSize = 5;//count($_products->getItems()); echo $_collectionSize; ?>
        <ul class="products-grid" id="products-grid-table">
          <?php $i=1; foreach ($_products->getItems() as $_product): ?>
          <li id="td_<?php echo $i;?>" <?php if($i%5==0 or $i==$_collectionSize){echo            'class="last"';} ?> >
            <div id="cont_<?php echo $i;?>">        
                <a class="product-image" href="<?php echo $_product->getProductUrl() ?>" title="<?php echo $this->htmlEscape($this->getImageLabel($_product, 'small_image')) ?>">
                    <img src="<?php echo $this->helper('catalog/image')->init($_product, 'small_image')->resize(135); ?>" width="135" height="135" alt="<?php echo $this->htmlEscape($this->getImageLabel($_product, 'small_image')) ?>" title="<?php echo $this->htmlEscape($this->getImageLabel($_product, 'small_image')) ?>" />
                </a>
                <h3 class="product-name"><a href="<?php echo $_product->getProductUrl() ?>" title="<?php echo $this->htmlEscape($_product->getName()) ?>"><?php echo $this->htmlEscape($_product->getName()) ?></a></h3>
                <div class="a-center">                        
                    <?php if($_product->getRatingSummary()): ?>
                        <?php echo $this->getReviewsSummaryHtml($_product, 'short') ?>
                    <?php endif; ?>
                    <?php echo $this->getPriceHtml($_product, true) ?>
                    <?php if($_product->isSaleable()): ?>
                        <button class="button" onclick="setLocation('<?php echo $this->getAddToCartUrl($_product) ?>')"><span><span><span><?php echo $this->__('Add to Cart') ?></span></span></span></button>
                        <div class="clear"></div>
                    <?php else: ?>
                        <p class="availability"><span class="out-of-stock"><?php echo $this->__('Out of stock') ?></span></p>
                        <div class="clear"></div>
                    <?php endif; ?>
                    <ul class="add-to-links">
                        <?php if ($this->helper('wishlist')->isAllow()) : ?>
                            <li><a href="<?php echo $this->helper('wishlist')->getAddUrl($_product) ?>"><?php echo $this->__('Add to Wishlist') ?></a></li>
                        <?php endif; ?>
                        <?php if($_compareUrl=$this->getAddToCompareUrl($_product)): ?>
                            <li class="last"><span class="separator">|</span> <a href="<?php echo $_compareUrl ?>"><?php echo $this->__('Add to Compare') ?></a></li>
                        <?php endif; ?>
                    </ul>
                </div>
            </div>
        </li>
        <?php $i++; endforeach; $kol = $_collectionSize; ?>
    </ul>
</div>
<?php endif; ?>

Now finally we have to call only the above code to display the most viewed products on our store page this can be done as :

{{block type="catalog/product_mostviewed" template="catalog/product/mostviewed.phtml"}}