I have to bow out from answering this, please dont take offense. I already have a headache, and reading your post made it worse, and responding would put me in Migraine mode.
I will say this..
for you say Halo 2 is the worst looking game...
something with your tv or xbox is not working, or
you havent set them up correctly
you obviously know very little about xbox games.
You say... "I see that some games are 480p"
I believe there are only TWO titles that are 480i only, meaning the other 4 to 500 are ALL 480p.
"The Thing" is one of them, I dont know the other.
are you even fugging using the HD pack and the Component connection?
migraine setting in
someone please step in, I can't take it.