I have a candidate, and I'd love to hear if you know better.
After being in New England and being spoiled by local dairy products (that the cheapest brand - Cabot's - would prove better than virtually anything I could find out here, I would not realize the wonder of before I re-arrived in the West Coast), here, I went on a long tour of dairy products, especially unsalted butter, which is utterly key to my way of life. (Link below to a discussion of a dish which lives on the quality of the unsalted butter.)
Tried all the organic butters at Whole Foods. Decent, too pricey. Tried weird butters found in weird places. Most of them tasted, at best, clean, but not full.
Finally, in Ralph's of all places, I picked up, on a whim, some cheesy I'm-So-Euro looking butter called Danish Creamery - and was astonished. A clean - not ostentatiously rich - but very full butter. Doesn't taste rich, not too intense, but complements everything wonderfuly, hangs above flavors without obscuring them. Cooks up with veggies perfectly, cooks up with salmon perfectly, astonishing on bread. I can't describe it really, but I've had bunches of people eating buttered toast stop, remark, pick up the butter and inspect the packaging. I've had people ignore the jam and just eat lots and lots of buttered toast. It's very odd. It isn't particularly expensive, not nearly so much as organic butters at yuppie-marts.
If you know better, or equal-but-different, let me know.