At Optimum7, we get this question a lot. And honestly, it’s a tough question. 

The most truthful answer is that it depends. We understand, many people find that response frustrating, but it's accurate. If you just have a couple of products, and you're simply trying to start something small, but you don't really have a business plan, then your needs are different from larger operations.

If you're not really trying to grow because you're just testing stuff out, then you can use an open-source solution, like WordPress or WooCommerce. If you want to be serious, then we always recommend Shopify or BigCommerce.