But Louis' cafe - one in Heath Street, Hampstead, and the other on Finchley Road, Swiss Cottage, are great institutions... This is the Hampstead branch.
You haven't been? Get there now!
My other regular haunt is of course the inimitable Wet Fish Cafe on West End Lane - we love it, love it, love it...
http://474towin.blogspot.com/2008/06/wet-fish-cafe-is-just-best.html