Shopify Pro - Slick UI - Solid backend to manage products - Good plugin support with other e-commerce giant like Amazon, eBay - Good community support - Flexi

Shopify Pro - Slick UI - Solid backend to manage products - Good plugin support with other e-commerce giant like Amazon, eBay - Good community support - Flexible store customization with good range of theme - Easy to manage even for even non-IT person(Taking about backend process like product listing, shipment generation etc...)