It depends on your taste....but in my opinion, Phillipe's French Dip (they invented the French dip over 100 years ago) in Los Angeles, California.

Sandwich in English = Sandwich in French

for the sandwiches you find in the fast-food chains, use the same names you would use in English.
for a simple bread, butter and ham sandwich, ask for 'un jambon-beurre'
for a cheese and butter sandwich, ask 'un sandwich fromage'
a tuna sandwich with some salad, egg and a slice of tomato, is called 'un sandwich complet;
"un grec" or "un kebab" are mutton-based sandwiches with onions, sauce, French fries.
"un américain" is a sandwich with french fries in it.

A ham sandwich is "un sandwich au jambon" in French.

Sir Alfred "French" Dip III