The second best hamburger I ever had was in Indiana during the summer
of 1976 at a McDs of all places.
I think it was a test burger because when I returned to the upper midwest
where I was living at the time I couldn't find it and never heard of it again,
it was called a "McFeast",
built on a pastry style bun it was huge, made with sliced tomatoes,
fresh lettuce and all the other goodies a real hamburger should have.
It really was a damn good hamburger.
BTW, the best hamburger I ever had was the one I made last month
on the grill.