In game items would piss me off as I see them as removing content or potential content from the retail game and making it "exclusive", which leaves some people who buy the regular edition with a bad taste in their mouth as they don't feel like they're getting the complete experience.
I really want a stylish case. Something tin. I felt that Perfect Dark Zero's CE case was the definition of swish. I wouldn't want a sleeve, but something like it please.
Second for me is the art book. Third would be the cloth map, but you didn't give me a third option

I don't want the letter opener. I open letters with my hands. They do the job admirably. And I rarely get letters. I can't open emails with my miniature glass claymore. The soundtrack I'm not fussed about being included in the CE. If it's exceptional then I will gladly pay extra for it on its own.