I was testing out version 7.08 of this fullblown e-commerce solution and this one is the numer one no doubt.
First of all, installation. A wizard setting everything up for you.
Nice looking store GUI
Admin products
If I were to create an fullblown online store Comersus would be my choice. I mean, being able to offer variations (colors for example) and built in handling of selling digital goods, that's really nice.
Comersus shopping cart