I suppose that if you exclude hamburgers and hot dogs (neither served with butter on the bun), the favorite sandwich in the US is the PB&J (peanut butter and jelly, usually made with jam or preserves and not jelly - and NO butter).

A BLT is bacon, lettuce, tomato, and mayonnaise, usually on toast (with what you Brits call "streaky Danish bacon").

Grilled cheese sandwiches are usually spread with butter on the outside of the sandwich, and cooked in a frying pan until the bread is toasted and the cheese melted.

On other US sandwiches, butter is optional - it depends on how your mom made them when you were a kid.

We have hoagies or submarine sandwiches that are made on long pieces of French bread with lots of filling - but otherwise, I don't think we have alternate words of "sandwich."

When I ordered a pork sarnie in York last month, I wasn't sure what I was going to get. Good, though.... [evil grin]

-Joe Offer-