Honestly depends on where you want to be in the next 5 years and if you want to keep paying monthly for a system along with how much customization you want.

Hosted solutions you are limited to the features and plugins they offer you. When I say hosted solutions I mean Shopify, bigcommerce, magento go, Volusion.

Personally for all of our e-commerce clients we use Magento Community or Enterprise edition. The advantages of this are they own the site once it's down. The hosted solutions you're paying for space on their server but if you every want to leave you have to start all over on a new system. Magento is a very popular system and is owned by Ebay. http://www.x.com/

This is part of a blog post that I wrote but have not punished yet because it still needs some editing.

What about the hosted solutions Volusion, Big Commerce, Magento Go, etc?

While can build sites for Magento Go and Big Commerce we still like using Magento Community and Enterprise editions over any hosted solution. Main reason is with those platforms you don't have access to the code and you cannot make custom modifications. Also, their extensions, plugins, mods community is not as large. Here is a real life example...Most of my customers want their product SKU number to be displayed on the product and category pages. Since it is just PHP code I can just place the code where it needs to go and it will display. I have not found a way to do this on Magneto Go or Big Commerce. The bottom line is those systems are hosted solutions and you physically do not own the site just the content on it. With Magento CE or EE you own the site. The site is 100% yours and you can do whatever or move it to whomever you want. There are no limitations (except Magento does own the code to their software).

It comes down to what you want to do and where you want to be in 5 years. Do you want to own your site or pay a monthly fee along with do you want custom add-ons. Magento has a huge list of addons you can add to your site simple stuff like social media logins for facebook and twitter. Possibilities are pretty endless with Magento unlike the hosted solutions that give you what they want to give you.