If you don't have one already, a Microplane zester is an absolute must in your kitchen. The fine teeth enable you to take only the sweet and tangy outer layer of zest off a citrus fruit, leaving the bitter pith behind. If grating ginger, the zester will hold onto the majority of the stringy fibres and leave you with a fine mince you would have to slave for with a knife. Minced garlic, a snap. Nutmeg and even cinnamon can be grated super-fine and since you are using the whole spice, the freshness of flavour far surpasses any pre-ground product. A favorite with a lot of people is the job a Microplane does on Parmesan cheese - ultra light and fluffy, there simply isn't a better way to top off your pasta or Caesar salads.
There are some choices in design, which ultimately will come down to preference. Some are more attractive than others, and you can choose a couple different lengths or widths. The grating surface is the same in each case, so you can pick the one that suits you best, but I'll share a few observations I've noticed in my experience with the tools. As for widths, the wide ones will help if grating cheese, but for citrus zest, garlic or ginger, the narrow ones are just fine. Citrus fruits are round remember, and only a small amount of surface will be in contact with the grater anyway. I find that the narrow ones fit better into drawers and tool kits, so I tend to stick with that style. With regards to length, I used a full length one happily for years with no issue, but have seen over-zealous cooks bend them on several occasions, and once they've been bent, the metal is weaker at the folding point and the grater's days are numbered. My full length grater eventually got nicked by someone, so when I replace it, I went with the shorter model with a handle. Not that it was ever really any discomfort, but I basically never used the top part of the grater anyway except for holding, so why not get a proper handle and the shorter grating length will be inherently more resistant to pressure. I still have it years later and it still works like a charm. Perhaps the important thing to notice was that after my first microplane got stolen, there was no question that it needed to be replaced - my set of tools is incomplete without it. So is yours. CHECK IT OUT HERE.