Today I'm giving a shout-out to my A/V Receiver, the Denon AVR-4806. Yes, it's a little old by now, but not really, and the one feature it's missing (1080p HDMI upscaling and routing) is available as a firmware upgrade.
What else do I love about it? Its documentation! Holy shit, would you look at that? IR codes, its serial/ethernet wire protocol for controlling it, and its HDMI specs.
Wait, Ethernet? How have I not taken advantage of this before today? Must remedy.
After doing the three button incantation on the receiver to enable "Network Settings" in the menu (must hide it by default to not confuse people!?), I selected DHCP and it got on the network. I then read the aforelinked protocol docs and whipped up a stupid little interactive AVR-4806 controller in Perl. I love how the protocol is two way: you can tell it to do stuff, but it also notifies you of all changes to its state. I go twist the physical volume knob and I get immediate status packets back from it.
I'm thinking of giving my neighbors a webserver interface to the volume knob, so they can turn down the music if (when) my Wednesday night parties get too loud.