On my website I use reset.css. It adds exactly this to list styles:
ol, ul {
list-style: none outside none;
}
html, body, div, span, applet, object, ifra
You cannot. Whenever there is any style sheet being applied that assigns a property to an element, there is no way to get to the browser defaults, for any instance of the element.
The (disputable) idea of reset.css is to get rid of browser defaults, so that you can start your own styling from a clean desk. No version of reset.css does that completely, but to the extent they do, the author using reset.css is supposed to completely define the rendering.