Toshiba. Mines working like a champ
Look for the best bang for the buck, hdtvtest.com is a good reference. I'd get one with at least HDR and Dolby Vision. When possible, local dimming with reasonable performances. At this price range, you can't ask for much.
I paid $600ish for a 75in Philips Android TV on sale at Walmart. I judged my purchase by the biggest size I could buy for the same price that I paid years ago for the 40in that I was replacing. The Android OS was an attractive feature but I could have just as easily bought a Chromecast with Google TV and had the exact same experience if not better more than likely. Brands don't mean much on electronics as long as you don't go super generic.
None. Get the best TV you can afford in terms of display quality and add a ChromeCast with Google TV. You will get better performance and support.
Those TVs will probably be weaker than Chromecast.
Buy the best TV not the best Android tv