Perhaps one of the most visually appealing coffee makers on the market, this simple to use coffee maker has a scientific edge over the competitors. Once the water on the bottom heats up, it creates a vacuum that expels the expanding hot water up to seep into the coffee grinds above. After the grounds have been well saturated, all you need to do is turn down the heat, which diminishes the vacuum, and watch as the brewed coffee finds its way down below again. Feel a little lost? Check out this video to see a coffee siphon in action.