My cutting requirements are chosen for my specific needs. I have a large matt that I trimmed to fit my counter. My rotary cutting tools fit my needs. There are a medium sized cutter, both straight and pinking, for fabric and another clearly marked set for paper. Oh and new blades for each. I also have a package marked 'old' for used blades.
I use the medium sized one because it works best for the 2-4 layers of fabric I usually cut. I use the cutters for paper when making my Eye Candies.
An assortment of rulers, my most used 6" x 12". I thought that a 4" x 14" might be easier on my hands, but I am so accustomed to the larger one I just couldn't do it! My 6" bias square, it is most accurate for bias squares. 6 1/2", 8 1/2" and 15" square rulers, I only use them for squaring up blocks. I don't seem to do well with the half-inch thing any other way.
And last but not least InvisiGrip! Made by Omnigrid to prevent rulers from slipping when rotary cutting. (All my newer rulers are Omnigrip™ by Omnigrid® green of non-slip rulers.)