Can anyone direct me to a link to or have an official list of certified Android TV devices and their specs including well-known ones like the Chromecast with Google TV and the Nvidia shield? I'm curious as to how many Android TV devices exist and which ones are worth the effort
androidtv-guide.com is a great resource, but if you're looking for an official list, the only one out there is the Google Play Console's Device Catalog with the "device type" set to "TV".
Accessing this requires having a Google Play developer account, which costs some $$$, so you're better off sticking to androidtv-guide.com .
Android TV Guide