
eCommerce or Ubercart
If your site is big you might want to consider eCommerce becuase it has more options. But for the small site, it's quite heavy.
But if your site is small - try ubercart which provided better usability the last time I tried it.
Review by levavie [info] on July 15, 2009 - 05:45

The best Drupal ecommerce option
I've tried using eCommerce and Ubercart and while Ubercart is very new and shows a lot of promise, the eCommerce suite of modules is by far the best option for an online shop on a Drupal site. Particularly if you need more payment options, flexibility and features, Version 4 is in beta, but, for production/live sites, go for version 3.
The key strengths of eCommerce would be the volume of add-on modules and it's flexibility. It's a large suite of modules and takes a little getting used to, but, I found it much easier to theme and tweak the layout or elements such as the checkout screens. Having tried Ubercart a few times, I've always found myself getting stuck and going back to eCommerce.
Tip: Both Ubercart and eCommerce are tricky to uninstall completely, so always try them out on a test site first.
Review by Gus [info] on March 23, 2008 - 13:34

Not particularily flexible
I've used the Ecommerce 3.X releases on several sites now, and I have never been terribly impressed with it. It is somewhat difficult to configure. The API and documentation are quite poor, and there is little to no community support to help you work out any issues.
The development team suggests that many of the issues with Ecommerce 3.X are fixed in the 4.X releases; however. the 4.X releases are still alpha at this time (and have been for many months), and are not yet suitable for production use.
I would heavily suggest that any potential users check out Ubercart first; if your project can be implemented with Ubercart, you will be able to take advantage of an excellent codebase, intuitive API, and responsive, knowledgeable community!
Review by BrianV [info] on March 3, 2008 - 14:42