For many people in the United States, stove-top kettles are king. They're affordable, they heat water pretty quickly, and some even whistle when the water reaches its boiling point. Electric kettles tend to be more popular in countries where tea is preferred to coffee, but they have advantages anyone can appreciate.
For example, electric kettles boil water more quickly, so they're more energy efficient. They also free up burner space on the cooktop or range, and can be used in places without access to a stove; say, at the office or in a bedroom. And of course, hot water comes in handy for hot chocolate or instant oatmeal and soup as well as tea.
Material options: Electric kettles may be made from plastic, glass or stainless steel. Plastic is the most affordable option; glass offers the option of viewing your water or tea but can crack or break; stainless steel keeps the water hot the longest, but makes the kettle heavier to lift.
Corded or cordless: A corded kettle sits on its own base and has an attached cord that plugs into the outlet. A cordless kettle sits on a "plate," and the cord is attached to the plate. They work the same way, but the cordless option makes pouring and serving easier.
Nice features to look for include a water gauge to indicate the level of the water inside the kettle, a water filter, variable temperature control with different settings for different types of tea, and an automatic shut-off function so that the kettle doesn't boil dry.
Kettles typically cost between $20 and $100, although they can run as high as $250 if they have a lot of features.