For my money, they are all pretty much the same at the top end. We are talking a matter of degree, or a half of a degree difference.
Obviously the cheap stuff is...well... cheap, and you get what you pay for. Low milk fats replaced with hydrogenated oils, carrageenan added for texture and imitation vanilla.
Prepackaged ice cream is prepackaged ice cream. Find a small local ice cream/candy shoppe. We have one here called Dewars. Their Black and Whites are to die for and they ship their chews all over the world. I am fond of the peanut butter chews. ;)