For tv/movie setup I would definitely separate the audio from the video as millercarbon stated and use a top of the line video picture format like OLED, which is a bit more expensive but picture quality can't be beat by any other currently available technology.
For audio, the sound from just the tv might be acceptable for some but everything will sound significantly better through at least a 5.1 home theater surround system. The "5" represents 5 channels and speakers ( front l+r channel main speakers, a center channel speaker and rear l+r surround channel speakers) and the ".1" represents a subwoofer.
The most efficient and least expensive method to achieve a good quality 5.1 or 7.1 system (7.1 just adds a pair of l+r side speakers) is to buy a high quality blu-ray player, such as a new or used Oppo player among others, that has a built-in 5-7.1 surround channel processor along with analog outputs for all 5-7 audio channels along with a sub output. You'll just need the speakers, rca cables and amplification.
The Atmos surround format adds a pair of ceiling channels with devoted speakers for height perception that some prefer. I've always preferred a high quality 5.1 system with 2 or more subs for a good balance between sq and simplicity. For Atmos, you'll need the video source content software and surround processor hardware to be Atmos compatible.
I'd suggest auditioning some good quality 5.1 to Atmos systems with one and multiple subs to determine which you prefer. I also think you should look into a multiple channel solid state class AB or D amp to drive your multiple surround channels, the sub(s) typically are self amplified. SS multi-channel surround channel amps will produce less heat, are more efficient and more reliable than tube amps, especially for home theater use.
Tim
