I LOVE Isigny Ste. Mere butter, when I can find it.
http://www.isigny-ste-mere.com/
Here’s a great online gourmet source, for it:
http://www.igourmet.com/search/search.asp?keywords=Isigny+Ste.+Mere+butter&search.x=20&search.y=5
And another:
http://www.cybercucina.com/