I shop for elite televisions at the “reuse” center, my latest score was a 2013 Panasonic plasma which is a perfectly good dumb TV hooked up to an XBOX ONE and a home theatre. Downstairs I have a big curved Samsung 4K attached to my big PC. Someday I’ll see the high end OLED that I crave.
If you have the room and price is no object you definitely want at least 5.1 theatre, both movies and TV programs sound great in 5.1. The next step up is a second subwoofer, even for music subwoofers take a load off your other speakers and reduce distortion.