Netflix question - best streaming device for an old "smart" TV?

[AZJonnie]

6. Define "best"?

Just so you know, the oldness of the TV becomes irrelevant in almost all streamer scenarios (as long as the TV is 1080p or above, and has HDMI inputs, any streamer will work). As someone mentioned above, the Shield is one of the 'best' (I have one) but it's also overkill for most people. It's the best one if you have a full blown Atmos home theater system, and/or a large collection of blu-ray rips on a hard disk and want to use it's built-in Plex server functionality to watch them, for example. An Apple TV is also a top of the line streamer, more user friendly than a Shield, and its stronger than the Shield (feature-wise) for the average user, but it's also pretty pricey.

If by 'best' you mean one that plays Netflix for as little money as possible, that's a whole different question. Not sure why you think no Chromecast model works for NF? This one definitely does https://www.amazon.com/Google-Nest-GA01919-GA01919-US-Chromecast/dp/B08KRV7S22. There's also various Amazon Firestick options. If it were me I'd probably look for a used Apple TV on craigslist or the like, but not sure if that's the right choice for you.