The best tool to have in your kitchen is a sharp knife. No joke, just a very sharp chef's knife.
A sharp knife is safer than a dull one. I know that sounds counter-intuitive, but it's true! A dull knife can slip while slicing, and the pressure you exert on dull knife is greater than that which you put on a sharp one, which can lead to fatigue, and sloppy slicing. In my personal experience, I have also found that I am much more focused and careful when using my awesome, sharp chef's knife.
