Good, customizable php e-commerce package?

[younify]

Hello,
I build database sites in PHP and MySQL. I've built a cart before, but I would rather use a third party e-commerce system, if i can find a good one that I can completely integrate with my html front end.
any recommendations? Free solutions? Solutions that cost a little dough?
Thanks!

[alanzhao]

I prefer to use my homemade shopping cart.😃

I heard osCommerce is pretty good.