In Search of Best Online Shop for WP

I have tried searching through the plug-in files for the best Shop Plug in to use with WP. I have tried several but some do not even work.

I would like to use this to sell downloadable products through my site. and have a simple cart systemt hat users canuse paypal with.

can anyone recommend soemthing they use or have seen that works well with current WP version.

Thanks