We've been in our house for 10 years now, and we're finally starting to think about actually using our media room for its intended purpose (rather than using it as a giant closet).
The room is pretty large, 13'6" x 18', so it really needs a 75+" screen. It is pre-wired for both side and rear speakers, and the positioning of the connections makes me believe that a 5.1 setup won't work well. (The side speakers connections are literally beside the main seating position, and the rear speaker connections are only about 5' apart.)
Budget for the A/V equipment (TV, AVR, subwoofer, and speakers) would be about $4,000, so goodbye OLED dreams.
I haven't purchased anything more complex than a replacement TV or a soundbar for a number of years, so spec'ing out a full-on home theater system is a bit overwhelming. In particular, it isn't clear how a $4K budget should be allocated between the various components. A simple Google Shopping search, for example, shows 75" LED TVs for anything from $800 to $2800; speakers and receivers have similar wide price ranges. So I could easily spend $2800 on the TV and only $1200 for all of the audio components or vice versa.
I'd love to get some ideas on how to "balance" a setup like this.