According to DigitalTrends.com, some of the best devices for streaming content from a PC to a TV are the Roku, Amazon Fire TV and Chromecast. All three devices connect to a television HDMI port and allow streaming of media from many popular computer applications. The Roku and Chromecast also allow users to mirror their PC desktops on the television, treating it as an additional screen.
To mirror a PC desktop to a television using Chromecast, open Google Chrome on the PC, and install the latest Chromecast extension. Follow the instructions to connect to the target Chromecast. Click on the cast button in the top right of the browser, and select Cast screen/window. Other casting option include the current Chrome tab and popular web applications such as YouTube.com and Netflix.
To mirror a PC desktop to a television using Roku, navigate to the device's settings menu, select System, then select Screen Mirroring, and choose Enable Screen Mirroring. On Windows 8, open the Devices menu, select Project, click Add Wireless Display, and find the Roku. This allows you to use the Roku like any other display attached to the computer.
Roku and Amazon Fire TV are set-top-boxes which can be used without a connected device. They are also both available in smaller versions that operate similarly to the Chromecast and may be preferable to the larger versions for PC to TV streaming.