Market
Some of the features of this include:
1. It is a revolutionary theme.
2. It transforms your site into a fully featured ecommerce store.
3. It gives you a complete backend product administration.

Visit The Theme Site

1. WordPress Shopping Cart Plugin
Some of the main features of this plugin include-
1. It gives you the functionality of online shopping
2. You can give images to your products to let the customers know what they are purchasing.
3. Customers can download digital products.

Visit the plugin Site

WP e-commerce
Some of The main features of this plugin include-
1. Integration with Google Checkout, Paypal etc
2. It gives your customer a good experience of shopping online

Visit the Site