CSS - Table design
I think I've used GridViews in pretty much every application I've built using ASP.NET, and as such they are something that I always end up styling via CSS. They render as a table which makes it easy to apply the same style right across your application to keep a consistent lok throughout your site.
I recently stumbled across a site at http://icant.co.uk/csstablegallery which has a list of ready made CSS designs for tables which you can freely download. There's some good designs on there and it's also a place where you can submit your own designs, so if you've got any CSS that you use add it to the list for others to see and use.