The graphic design section for Stack Exchange has this grid background that makes reading questions and answers difficult. I think a plain white background would be much better in place of the grid background.
Being a graphic designer and programmer I find Stack Overflow more pleasing to use and graphically cleaner.
What you see right now is the "sketchy" theme -- we use it for sites that don't yet have their own look-and-feel (something typically added at graduation from beta). It's not unique to graphicdesign.SE, so we're not going to do a bunch of custom tweaking. Instead, put your time into deciding what your permanent theme should be like.