Coarse Grater from Rosle fits the bill for fast and easy salad prep.
You can find cheaper graters, but they are not such a pleasure to use and will need to be replaced from time to time. The Rosle will probably never need to be replaced. It's made of quality 18/10 stainless steel and is dishwasher safe. I love that you can prop it right over a bowl and grate your veggies right in, or, because of the rubber foot, it remains stable on a cutting board. You could also use this grater for fruit, cheese, and chocolate. Find it HERE.