Fork = takeout eating at home, typical junk food buffet places, food court, I go for a fork. Better to shovel in my face with.

Once you step up to decent cooking, noodle dishes, dishes where the rice isn't slathered in sauce, sushi, and pho; I go for chopsticks.

Curries, fried rice, and other things that get the rice all saucy I stick to a fork.