The Roku Express (2017) is an affordable streaming bar that enables access to tons of content.

The Roku Ultra (2017) is an excellent value, especially if you can live with run-of-the-mill audio, but it's similar to last year's model.

The Roku Ultra lives up to its name, with 4K resolution, HDR support, digital audio, USB connectivity and more than 3,500 channels.

The inexpensive Roku Express offers a lot of channels, but an awkward design and sluggish performance undercut its value.

The Roku Streaming Stick (2016) is a well-designed, inexpensive, content-rich streaming stick that occupies admirably little space.

The Samsung UN40JU6700 has a sexy curved design and 4K resolution, but the overall picture quality doesn't match the high price.

The Apple TV's innovative Siri features, app store and beautiful interface make the premium worth it for Apple fans, but it lacks 4K support.

The Roku 4 streams in full 4K at up to 60 frames per second and has more than 2,500 channels, but it's familiar and a bit pricey.

Google's Chromecast Audio makes it easy to stream high-quality audio from most streaming music services to powered speakers.

The redesigned Chromecast offers improved performance and makes it easier to find movies, shows and audio to stream.