Unordered list not aligning all the way to the left in a div

set padding,margin 0px,

#menutop ul {
    padding: 0;
    margin: 0;
    list-style: none;
}

Demo

http://jsfiddle.net/tQb75/

ul and li have margin or padding, depending on the browser, by default. You need to override this default style within your menu:

#menu ul, #menu li {
    margin: 0; padding: 0;
}

See a demo here

^{Note: By default, jsfiddles does a CSS reset, so is not always well suited for testing this kind of thing. Make sure to disable "Normalized CSS" when looking for this kind of bug.}