Before you buy a TV decide on the following features:
HDMI ports.... how many do you need I recommend 1 more than you have devices for at the time. I have 3 on my TV when other brands in the price range only had 2 of them and I am using all 3 for a Blu-Ray player, OTA DVR and and Sony 5x DVD changer
Optional ports like audio if you plan on connecting external audio to it make sure it has the right port for it if not HDMI.
Streaming support for favorite apps/services
Remote that you like with function you use often.
I have a 2 year old Vizio 55 inch TV with Smartcast that is pretty decent. I started with about 75 apps but over time now up to I think around 130 apps. There were cheaper TVs but they did not have remote functions for things I needed like changing aspect ratios directly I looked at Fire TVs and Roku TVs and the remotes were bare bones. My advice is when you get your TV, look online on Ebay and Amazon and get a spare remote control for it. I picked up a different model remote for my vizio for $5 that had one function on it that the newer remote didn't include. Since I have my TV in my bedroom I have a remote near my computer table and one near my bed which makes it so when I want to watch TV in bed I don't have to carry the remote.
75 inch is pretty big you would need a big room otherwise you will get whiplash too close watching a ping pong tournament.