I'm cheap, and always have been, so it's an easy choice. Google has made this immeasurably easier.
There are a number of TVs in the house, and I have this thing called "wifi".
I picked up a couple of the Google Chromecast dongles for $25 each, and they go in the TV. We have Android phones in the house, so we use Chromecast to stream pretty much everything to the TV - Amazon Prime, Netflix, or the local Plex server.
Local media (movies and audio) are kept on a FreeNAS box, and Plex is one of the trivially configured plugins available (through the FreeBSD jail system).
I also have wireless HDMI adapters, so that solves the "I want an extra monitor while I'm working from the living room" problem.
I also have a rooted Wii (with eg. dlna client) and a Blueray/DVD player, so there are alternative means of streaming if an Android phone isn't available... but there are at least 6 in the house...
If I had a stereo to speak of, I'd just use something like the Chromecast Audio dongles for the same functionality (or maybe, this: http://www.amazon.com/Kinps%C2%AE2-Switch-Splitter-Input-Output/dp/B00NNHWRGW/ref=sr_1_2?ie=UTF8&qid=1445449981&sr=8-2&keywords=hdmi+switch+2+out)
Conveniently, all my media is also available through Plex wherever I go with Internet access.
Really, the only limit for full home automation is your budget, at this point. it's trivial to do with ubiquitous home automation kits... My favorite is Ubiquiti brand.