I was never considering Cheddar to be a real cheese. It's very artificial in taste for me.

In generakl, the rule is the younger cheese, the less fat it contains, so the best are young cheeses, like ricotta, cottage cheese, mozarella. Then in the middle we have edam, gouda, Emmentaler and others from the mainstream "yellow" types, and at the end there is a blue cheese, parmesans, grana padano.