I have a couple of these:
Sonos Play:5 review - Engadget
it works really well. No remote controls, no speaker cables, USB-connections etc.
I can instruct it to play web radio, my own MP3's or music from Spotify. I can do it through IPhone, Pad, laptop or whatever that supports their app. I can group all of them to play the same thing or let them play different things in different rooms. And if I ever think that built-in speakers are not enough (which they are in 99% of case), there is a Sonos Amp that can be connected to external speakers.
Best of all, they are completely stand-alone so I don't have to keep my device feeding the data to them (except if I want them to play mp3's, which they read off a small server). You can switch off your phone/laptop/ipad and it keeps on playing.
I also have a reciever/speaker/media player/stuff combo that I don't bother using anymore. Why fiddle with all the controls when all I need to do is take my phone and say "play that in that room" and boom, it does.