Best ecommerce cart?

I am looking for a cart which is free and something really simple that will be used for a florist.

I am also looking a simple theme, not something with many modules as the owner is a complete beginner!

so something sweet and simple..

any ideas?

If you're using WP you can try WP Ecommerce. However, the support sucks. I suppose that's what you get when you use a free cart. Don't bother purchasing the gold cart add-on. It's not worth the money.