I'm not saying Virtuemart is the best solution, by any means.
Look at this topic alone, the varying opinions of all the different systems goes to show that it really does come down to personal taste.
I have only used VM for a client that had a small, fixed product catalouge. It works well for him, required minimal extra skinning (it took 95% of the main sites skin), and was easy to setup and maintain.
I have used Magento for a client that ran an online kids clothing store, I hated setting it up, hated skinning it, and my client hates using it. All round was a fantastic project!
haha