I wish Beautiful Widgets and Weather Widget Donate would get together and make the ultimate set. I don't have my Droid yet, but from what I've read that both seem to have holes that the other fills nicely.
Weather Widget is skinnable and has tons of cool skins to try out and has some slick animations once you click on the weather icon. But it has some issues with updating properly-GPS always on trying to find your location, problems with sunrise/sundown icon delays, weather only updates manually. Beautiful Widgets has only the one type of clock and doesn't have quite the bells and whistles, but seems to have perfect functionality.