I find Zen to be a better starting point than any core theme. It's well supported and documented and easy to use. Out of the box, it is very "clean." I always add a site-specific CSS file for changes that I don't want to include in the base CSS files.
Nancy Injustice anywhere is a threat to justice everywhere. -- Dr. Martin L. King, Jr.
From: Roger
I need a clean 3 column fluid width theme with no borders or edges and simple template and css files, I find the garland theme easy enough but the Bartik theme is very complicated, more than I need.