Well then it's your problem! Allow me to claim that if it looks bad to you it's because you were lazy. The possibility of changing the defaults in the browsers is really there because tastes are different. All the pages without "styles" allow you to see them better than the others where the style is forced on you, once you adjust the default style. You set that only once for all such pages you're going to see. It's worth, much more than applying something every time you come to some such page which is what your suggestion was.
How can anybody know your personal preferences? I also can't teach you how you should set them as I don't use the same browser as you. Try to remember: not everybody uses everything you do.
I don't understand what your problem is, apart from not knowing to use your browser. You've asked for a tool, you've received the answer -- it already exists, you're not accepting it again and again.
