We loved the Costco (Kirkland) organic brand...but then a few months ago they stopped carrying it
On my last trip to Costco (we have a big family, we're usually there at least once a week!) I noticed a new item that was a Kirkland brand "natural" peanut butter. I haven't tried it yet but plan on buying it next trip.
While we couldn't get the Kirkland organic brand, I switched to Smuckers Naturals. I think it's pretty good. If you're used to the more processed brands, it may take a while to get used to the natural or organic types. But after you are used to those, the processed types will taste gross!
We've been eating only natural/organic types for several years now. A couple years ago, our fridge broke, and organic peanut butter needs to be refridgerated. We had just one of those mini fridges for about a week while we waited for a part to fix our main fridge, so to save space we used the shelf stable, processed type. I couldn't even eat it...my kids were ok with it, but said they preferred our regular (natural) type.