Remove bullets from WordPress Popular Posts plugin

Trying to remove bullets (and possibly add thumbnails) to the Popular Posts widget found on the sidebar at http://www.godoflamb.com – managed to do the latter but the result was awful. Not a great coder.

My priority right now is removing the bullets, which seem to be messing with the styling quite a bit. I tried checking “custom html” and removing

and

, but they return as soon as I save the widget.

Any ideas? Is there another, better (simpler) plugin?