I'm finding that I want a larger cutting mat than the basic 18x24 that I've had forever.
I'm also wanting a larger/better design wall than the flannel side of a flannel-backed tablecloth that I'm currently using. Thinking of getting 2 yards of a neutral color fleece.
Other than those two items, I prefer to keep my tools fairly basic and not burden myself with tons of "gadgets". Note - I do find certain templates very helpful (square, hex and diamond come to mind).