Raspberry Pi. A lot of the use of xBMC and subsequently Kodi was on the Raspberry Pi a year or two ago, but it’s difficult to get it to run with good performance without hours of tweaking. Once you get it working, it runs great, but there are better alternatives out there now like the Fire.
Where it really helps is when you have something that isn’t available anywhere. For instance, for awhile, District 9 was not available on iTunes or anywhere else for that matter, so you could get it on Pi. Or if you like watching “The Soup” you can’t get it without a cable subscription.