There are two types of steaming gadgets: set-top boxes and HDMI sticks. HDMI sticks are the size of USB drives and plug right into your TV's HDMI port. That means less clutter in your entertainment center and they're also cheaper.
(Bonus: Need more help choosing the best video streaming option? We have other helpful charts that will help you make an informed decision. Click here to see the chart comparing streaming media player boxes, and here for a comparison of streaming service channel line-ups.)
Here is a chart comparing popular streaming sticks: