The hockey-puck-size Apple TV is $99 and includes a remote control. It requires an HDMI cable, an additional $10 cost. Most of the services supported require a monthly subscription or on-demand fees.
Google's Chromecast is just $35, but does not include a remote control (there are apps for that), and requires a smartphone or PC to work. It plugs directly into a TV set's HDMI port, and no additional cable is required.
The $99.99 Roku 3 is the company's top-of-the-line set-top box. It includes a motion-sensitive remote control and earphones that plug into the remote. As with Apple TV, buyers need to purchase a separate HDMI cable.
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Pricing for on-demand movies is similar across all three devices, with some movies available for as little as $2.99 to rent and other more recent releases costing $16.99 or more. On Apple TV, you can purchase or rent titles from iTunes, whereas Roku supports Amazon Instant Video and a few other services. Chromecast works with Google Play videos or any Web-based service, as long as you cast it from your PC.
Prices for streaming-service subscriptions vary, but Roku offers the most free services, including music services. All three support Netflix, Hulu+ and HBO Go.
Winner: Roku. On an annual cost basis, Roku edges out the cheaper Chromecast and Apple TV. Because Roku offers extensive free services (more than 1,000 channels) and better pricing on rentals, owners of this device are likely to spend less overall.