We have an entire detailed guide on this 🙂 . We’ve covered most of the major WordPress eCommerce plugins / platforms, and all of our reviews are detailed and unbiased. You can start with the conclusions and work your way through the guide if you’re just starting out, or pick some of the plugins on your short list to learn more.
For physical products, my favorites are WooCommerce, Shopp, and Exchange. WooCommerce and Shopp have far better order management capabilities, and will scale better with your store – we’ve got a head-to-head comparison coming up soon.
WooCommerce is lightweight and favors the add-on model, while Shopp builds a lot more into the core plugin and is therefore less expensive. However, you may not end up using everything that it offers and you’re needlessly running a lot of code in that case. The add-on model with WooCommerce also provides more opportunity for customization. Exchange is lightweight as well, but geared towards ease of use and can work well for clients that want to manage a lot of their own sites.
For digital products, I usually use Easy Digital Downloads or WooCommerce. Both use an add-on model and can allow you to manage downloads and licenses effectively – I prefer EDD for digital-only shops, but WooCommerce for stores that will be selling more than a couple of physical products or I’ll need a particular extension.
In some cases, I’ve also found Cart66 Cloud to be a good choice, especially if you’re selling memberships in addition to different products (Exchange does this well, too). Cart66 offers a blended approach and offers a hosted solution that removes your responsibility for any payment security.
You may need a different plugin than one of my favorites, so I recommend reading through our guide to get an idea of what’s important to you as you launch or migrate your store.