Yep, Kerrygold butter from Costco is our butter of choice. (Once or twice DH bought home some Kerrygold cheese, but it was gone before the groceries were unpacked.)
Funny story about how we learned about it in the first place.
A number of years ago, DW was at a friend's house and tried some Kerrygold cheese. She really liked it and told me to look for it (I do all the grocery shopping). I accidentally grabbed the butter instead of the cheese, and when we tried it we were blown away by how good it tasted. Nothing else in our house ever since!