Once you've chosen the type of microwave you wish to use there are a number of other features to consider. Just about every microwave from the simplest to the most complex will perform the basic functions of cooking and defrosting.
In this regard the main difference is wattage. Wattage is the power a microwave uses and it can be loosely related to how powerful the appliance is. The higher the wattage rating of the microwave oven the faster it will heat the food. Microwaves range in wattage from as low as 350 watts to a powerful 1350 watts.
However, purchasing a microwave oven on wattage alone may not get you the best product. For example, larger microwaves need a greater wattage rating to produce the same heat as a smaller microwave. Consider the power, but be sure to invest in a product with some of the features listed to get the best results for you.
Some microwaves include sensors which allow them to automatically adjust the heat as necessary. Using a sensor, the microwave can automatically detect when the food is ready and turn itself off. Sensors also allow a microwave cooks the food evenly, ensuring there's no cold patches in the middle when the outside of the food is overcooked.
The sensor can be used in conjunction with presets for common tasks, such as auto-defrosting, baking potatoes, or popping popcorn. High-end models include sensor technology that manages temperatures very precisely, melting butter evenly without splattering, or defrosting food faster and more evenly.
It's also a good idea to choose a microwave with controls that suit your needs. Many microwaves use touchpad controls and have settings for weight, power settings, as well as one-touch presets for specific types of food, including multi-session cooking presets. Multi-session cooking presets are useful if the food must be cooked at different power settings over the period of time, or if the food needs to be turned over or stirred mid-cooking time. Cleaning and maintenance of the oven is important too, so look for a microwave with removable turntables trays, non-stick interiors and grease filters if necessary.
There are some models that combine microwave heat with the heat from halogen/quartz lights, allowing them to brown baked foods and grill meats. Alternatively, some microwave ovens include special pans and grills and can be used to bake or fry foods.