pacanis, a good crusty bread can be many shapes and varieties, as you've assumed.
but the crust should be hard and fairly thick, upwards of 1/8th of an inch or more. not like the soft, thin crust of, say, a wonder white bread, or even the thicker but relatively chewy crust on a good polish rye. lika andy mentioned, it shouldn't bend much before it cracks.
i've had good, crusty bread in lots of forms: from round whites, ryes, and pumpernickels; to oval portugese/spanish style; to longer, fatter italian white or semolina; to even longer thinner french.
we have 2 great bakeries right up the block from us (1 italian, 1 polish) , so i often pick up a fresh, still-warm loaf on the way home from work.
just to guild the lily, if the bread is cold - but still less than a day, we often pop it in the oven to reheat and recrisp the crust. a lot of people don't do that at home, but it makes a world of difference. all of the aromas and nuttiness come right out again. try it, you'll see.