To the person new to SharePoint (MOSS and WSS), the UI out of the box is pretty darn cool looking. It is very functional and is polished. However, if you've seen it on more than one site then you're probably already sick of it. When I got in to styling SharePoint, I wanted to just do something simple. What I needed then was a set of samples, complete with images and stylesheets and a master page. I finally found something that I can use and implement in about 10 minutes with SharePoint Designer. On the Microsoft Office site, you'll find a set of 4 master pages with several color schemes each.