Me, I cut mine into quarters.
Everyone loves grilled cheese sandwiches. Even lactose intolerant people can say "yeah man, grilled cheese sandwiches look pretty awesome". I mean, who couldn't love melty, creamy cheese between two pieces of buttery toast? Gah, throw bacon in there and you've got my Last Meal.
The thing people can't seem to agree on, though, is how it should be cut. Growing up, my mom would cut mine into quarters, triangle-style (only grilled cheese, mind you...never PBJ or tuna), so to this day I think that triangle-style quarters are the only way to go. Others lean towards diagonal slices, other cut it horizontally. And then there are the blasphemous few that don't cut their sandwiches at all. Weirdos.
How a grilled cheese is cut is, to me, a personal thing. Whether it's processed cheese slices between Wonder Bread, or gourmet cheddar with pesto on focaccia, everyone wants their grilled cheese cut differently. Funny, isn't it?
How do you cut your grilled cheese?