I like the Olfa brand rulers.....one major issue to keep in mind is DO NOT CLEAN them with acetone, it removes the markings....ask me how I know !!!! Got spray basting all over mine favorate 12 x 12".....
.....another nice thing to have for your new rulers is a handle to help pick it up and the little dobers (looks like a 1/2" circle of hot glue) you can put on the underside to keep them from sliding on the fabric, very helpfull.....