For cooks, there are few things in the kitchen that are more frustrating — or dangerous — than dull knives. When you use one, you have less control. And a dull knife requires more effort than a sharp one, thereby increasing your chances of slippage and injury.Although using a whetstone or jig system is an aspirational ideal, those methods take time and effort to learn, plus you can risk ruining a good knife if either method is done improperly. Luckily, after we tested 24 electric, manual, and rolling-style sharpeners over the years, we’ve found a few models that are great for busy home cooks.Our picks, the Chef’sChoice 1520 and the Chef’sChoice Trizor 15XV, produce a keen edge, and they’re fast and easy to use. And both sharpeners can refashion even the dullest cutlery — whether Asian- or European-style, stamped or forged, cheap or expensive.