1- HDMI Switch

I don't know what kind of TV you've got but there's a good chance, you have more theater components than HDMI ports on your TV instead of getting a new TV or an a/v receiver you can probably get away with an HDMI switch you run HDMI cables from your set-top box or whatever to the switch then on a single cable from your switch to the TV.

2- network switch

 so many set-top boxes come with an Ethernet portو if your streaming video on something like a Roku or a Playstation you might be better served with a wired connection instead of a wireless one, if your router is close enough consider running an Ethernet cable to a network switch that lives in your home theater, yes it does create more cables to manage but your devices are less prone to interference.

3- speakers 

pretty much any external speaker system is better than the speaker's you find in your TV. you don't have to go all nuts with speakers everywhere but at least consider a sound bar moving on.

4- set-top box

you want to watch the Netflix or YouTube on your TV get some kind of set-top box. you can go as small as a Roku streaming stick or even get a gigantic thing like a game console, they all offer tons of streaming options if you go with an Xbox one or Playstation 4, you get the bonus of something that can play blu-ray discs or DVDs or CDs or optical discs still talking…

5- universal remote

there is no reason to have to juggle multiple remote controls when all you want to do is watch something in your home theater, one of our favorites as CNET is the logitech harmony home control it controls up to 8 devices including some smart home devices so if you wanted to sit back and have the lights dim at the same time, we do that with one button.

 for more top 5s check out top-5 science.gostten.com for Less top 5s skip to number 3 when you hit play up I don't know anyway I might as act harmless again.