The quality of bread is everything. Portuguese buns are the best, put them in the oven to crisp them off at 350 for 10 minutes. You get the light fluffy inside and a nice crispy outside. One thing Americans aren't great at is your definition of "crusty" bread. Crusty is supposed to mean that when you bite into it, the outer crust crunches before you get to the soft fluffy bread inside. If it doesn't crunch like chips (crisps) crunch, it's not crusty, it's just bread.

True; bread is pretty important. In SF sourdough is pretty prevalent --and that's ok, but it's not my preference. It's too tough --at times a bit like leather, so I prefer other types of crunchy loaves. Dutch crunch or baguette-style or even kummelweck.