Just the opposite for me... I really prefer light on dark, because I prefer to not be staring into a lightbulb.
I like light on dark, as you say, but not bright on dark, as whacked said. Light gray or grayish blue / green on on black or dark, dark red is my preferred. I keep a .txt on my desktop with html in it to make font exactly how I like it. On sites that have bad colors, I just paste the text in between the innermost tags in the .txt, save as 'blah.html', and read at ease. :)
Super+M is one of the best key combos in Beryl / Compiz. It inverts all of the colors in the window manager, which is great for turning white on black web pages into black on white.