Magento Commerce is a great open source platform. Here are some extensions that will help your store stick out from the crowd and add vital functionality to your business.
1 – Shop By Brand

This extension creates landing pages for each of your brands, which include information such as Brand Name, Logo, Description etc… The landing page will have an SEO link like this www.example.com/brands/sony.
Extension Page | Demo | Price: $99.99
2 – MouseOver Image Zoom
This extension replaces the default Magento image zooming feature. When you mouseover the image it will open a box to right where it will zoom into the image (sort of like Endless.com).

Extension Page | Price: $0.00
3 – Blog
A blog built from scratch for Magento. It’s not as extensive as WordPress or Movable Type, but it has all the basics. Should get you from point A to point B.

Extention Page | Price: $0.00
4 – Drop Shipping Management
If you do a lot of drop shipping you will definitely need help managing your orders. Magento is a great system, but it has no Drop Ship management features. This extension is pretty robust with a price tag to match.

Extension Page | Demo | Price $500.00
5 – Minimum Advertised Price
If you sell products that are protected by a manufacturer’s minimum advertised price policy (MAP), then this is for you. As always, rules are meanato to be broken. You can use this extension to work around the MAP policy withour ruining you vendor relationships.

Extension Page | $149.00
6 – QuickBooks Integration
This is vital for survival. Accounting is key to the success of your business. This extension will synchronize your orders with QuickBooks. Definitely worth the price.

Extension Page | Demo | $250.00
7 – Ticketing System
This extension will help you keep track of your customer service inquiries. It will help you save time by managing your workflow and will ensure that no emails fall through the cracks.

Extension Page | $0.00
8 – Color Swatches
Selling something in multiple colors? T-Shirts, Faucets, iPods? This is for you. It will add the ability to put color swatches and change the image based on the color selected.

Extension Page | Demo | $69.00
9 – Exploded Menu
Replaces the standard drop down menu with an exploded menu featuring multiple columns. Comes in handy when you have many categories.

Extension Page | $0.00
10 – Useful Product Downloads
This is great if you want to give your customers the ability to download PDF specification files for products. Just upload any file type and you’re done. Easy. Easy.

Extension Page | Demo | $49.00
More From This Series: Magento Extensions

Above given Extension are helpful to have more development over the E-Commerce website store. It builds up the stores and gives the integration of Shopping carts.
what about the fishpig plugin? http://fishpig.co.uk/wordpress-integration.html
Another great add-on that recently came out is an extension from http://www.nchannel.com that helps connect Magento with POS and Accounting systems. They are developing several different types but this company has some promise in terms of Magento connections.
Thanks for your cool ideas. I have run so many extensions on my store and the best powerful one is Gift voucher that I have used for 8 months and brings to me an amazing change. http://www.magestore.com/magento-gift-voucher-extension.html
We just launched an extension for tracking packages and sending shipping notifications at critical delivery statuses. Greatly reduce customer enquires about order status.100% free to track less than 500 packages each month.
Wonder if you can take a look and give us some comments? http://www.magentocommerce.com/magento-connect/aftership-track-package-push-notification-4124.html
Consider Magento Image Switcher with Zoom (compatible with Color Swatches) at more affordable price http://www.magentocommerce.com/magento-connect/product-configurator-for-custom-options-3163.html/
Check this private sale solution – http://www.plumrocket.com/solutions/private-sale-website-on-magento/ I think it looks nice, isn’t?
Hola una molestia alguna extension para Magento ver 1.7.0.0 para poner archivos PDF de los productos, tambien poner 2 precios mayoreo y menudeo o rollo y mts, alguna solucion espero su ayuda gracias
Great extensions of magneto thanks for posting such a nice blog about the magneto.
Nice article, but no information about RSS. RSS feeds are also very important for store promotion and this is one of the easiest way to increase sales. You can find a lot of extensions, but I always use for web-sites of my clients extension Noovias RSS Feed – http://www.magentocommerce.com/magento-connect/catalog/product/view/id/14879/ . It is easy in use and easy to configurate. Best solution on the market for nowadays, I think.
Hi,
Check this out – http://magentocrux.mavenstore.com/extensions-modules-addons.html here you can find useful Magento extensions and modules customized for your ecommerce online store. Download great Magento widgets and install instantly.
Nice list of extensions, but i wanna add one more great extension to the list – Improved navigation by Amasty. The trick is you kill two birds with one stone for a very reasonable price. You get such functionality as shop by brands, layered navigation, improved filters, variety of SEO features. i’m really happy with it and recommend to everybody! http://amasty.com/improved-navigation.html – it’s here.