Hands down, best shopping cart script?

[ceas]

I need a shopping cart script that is very customizable, banners, templates, colors, layout. I want a lot of integrated functions like search, bread crumbs, customer login.. etc. Any suggestions would be useful, free or not free.

 

[dezinerite]

Magento (http://www.magentocommerce.com/) is the most professional-looking free shopping cart software I've come across. I also installed it on one of my sites just to test it and it worked great.