I use Vim at least 100 times a day. And I like my terminals set to light on dark. Over the last 10 years or so you would find me in a dark office with a dark screen and bright text. I've since moved to a new office that is a little brighter but I still prefer the darker screens. With vi, the default syntax highlighting settings are too dark to actually read the text...the blue's are almost unreadable with background glare. So, a quick search revealed an option that fixes all my problems:
set background=dark
or
set bg=dark
Now my text is much brighter and still readable in the brighter office.
More: http://cephyr.cid.net/doc/vim/html/options.html#'background'