Honestly speaking, there's no best CMS out there, because what's best for others may not be the best for you.
And it's starting to creep me with the automated-like replies about magento going around here.
Anyways, if you're looking for the red herring called "best cms" then I assume that you know all the stuffs involving all the technical details and are prepared to get your hands dirty. If that's the case, then most reputable CMS dedicated to ecommerce will do it, such as, YES, Magento, Opencart, XCart and even CrystalCommerce.
Good luck, if you're not one who wants to get your hands dirty in code though.