Whenever I'm setting up a new apartment after moving, the first thing I do is figure out how to run an Ethernet cable from the cable modem (which generally ends up in the office) to the entertainment center in the living room. In my opinion it's a one time headache that will alleviate all kinds of issues down the line. Even though most of my devices have built-in WiFi I'm just old school and prefer the dependability of a wired connection.
The Chromecast has always been an exception since it is a WiFi only device. I get why. If you have a modern TV (with an HDMI-MHL port) you just plug the Chromecast in and you're ready to go. No wires, no fuss; it's a very neat solution.
If you have a slightly older TV, then you'll run a little patch cable between the Chromecast and a USB port on the TV, which is still relatively neat. But if your TV is as old as mine it might not have a USB port capable of providing power to the Chromecast. In that case you'll need to run a cable from the Chromecast to an outlet.
So now you have a wire running up the back of your TV but you still have all the potential drawbacks of a WiFi connection. Yesterday Google fixed that by introducing a Chromecast Ethernet Adapter for $15.
The beauty of this peripheral is that it doesn't add to the eye-level clutter at all. The adapter plugs into a wall socket (for power) and an Ethernet cable plugs into the adapter, down there at floor level. Then a single cable goes up to the Chromecast and provides both power and connectivity.
The only drawback, I guess, is the price. A $15 accessory for a $35 Chromecast feels a little bit wrong, but I think that has more to do with the Chromecast being so cheap. Maybe Google will introduce a bundle that comes with the adapter and a Chromecast for $45 or something, but since the adapter is already sold out I guess there's no need for them to start offering discounts just yet.