Recent projects I have been involved in have been interesting in using WordPress as an eCommerce platform. As time goes on it is getting easier to implement an eCommerce with payment gateways such as Realex Payments, Stripe, SagePay, Skrill, and Paypal. One of the major developments is the abundance of plugins to provide functionality needed to transform your website into an online shop. Plugins like WooCommerce, and MarketPress make it fairly straight forward to implement an online shopping cart.
Personally I like WooCommerce, and either Stripe or PayPal. While stripe is seamless it does need your website to have an SSL. PayPal which has improved over the years does the card processing on its site so your site doesn’t need to be.