Barcelona's best high-end/gourmet grocery store?

What would this be?   I just moved here and am settled into Castelldefels for 3 months.  I think the Carrefour here is ridiculously good- literally one of the nicest grocery stores I've ever seen!

Is there anything else in Barcelona that can one-up this one?

What about for organic/natural food. Is there anything here that specializes in that, something like a whole foods or natural grocers which I would find in Colorado?

Ametller is a chain of grocery stores with high end products and great produce, tho you should also go to some of the local markets, where it's brought in daily.