Price: $299 and up
Key apps: iTunes (audio only), Pandora, Rhapsody, SiriusXM, and Spotify
More info: http://www.sonos.com/system
Sonos isn't a single product; it's a company that makes a high-quality line of wireless home audio products for music, home theater, and streaming audio. As a result, you can choose just the right Sonos product, or products, for your needs, and all of them stream Internet audio. A good place to begin is an all-in-one wireless speaker like the $299 Play:3 or $399 Play:5. For a whole-house wireless audio system, add the $49 Bridge to connect all your Sonos devices. (Sonos also offers home theater speaker systems and devices that connect your existing speakers to Sonos networks.) They aren't cheap, but the quality is impressive. Sonos devices are iTunes-compatible, so you can send music from your computer to any room where there's a speaker, or you can stream Pandora, SiriusXM, Spotify, or other services. Free remote apps for Android, iPhone, and computers control the whole system.
Pros: Terrific sound quality; expandable system lets you create a housewide audio system.
Cons: Audio only; relatively expensive.
Price: $250 and up
Key apps: iTunes, Pandora, SiriusXM, and Spotify
A stereo receiver is the brains of your home entertainment system. All other devices plug into it to coordinate your entertainment. For instance, your Blu-ray player plugs into it to send video to the TV (also connected to the receiver) and audio to the speakers. (You can guess what they're connected to, right?) Because of that, many modern receivers include Wi-Fi or Ethernet support and offer built-in audio streaming. (Though not every receiver does, so make sure to look specifically for receivers that offer streaming.) There are dozens of receivers available. Which is right for you depends on your needs: how many devices you will connect, your standards for sound quality, and the price. Because there are so many options, and so many different possible situations, I don't recommend a single receiver but suggest looking at those from Denon, Oknyo, and Yamaha (what I have in my living room) to begin.
Pros: Powerful entertainment tool; versatile.
Cons: Can be expensive; not required for all home entertainment setups; the TV must be on to control streaming audio.