On my personal site, I have a black background, and at first I used white text. I got sick of the letters burning into my retinas (I would actually "see" the faint images of the text for a minute or so after reading the page) so I finally switched to a light grey text and it was a LOT better. For me. YMMV, which is why I allow the user to switch style sheets and offer a higher contrast choice.
The problem with designing for "everyone" is that everyone likes something different.