I've spent a lot of time looking over various grid systems. I must stay that 960 is the one I tend to use the most, I think it seems to be more main-stream. However, I do often consider other systems when I'm at the early design phase of my work. I wanted to do a post that was a comparison on the CSS Frameworks, but realized that there was already a good resource out there, so I might as well just link to that.