It depends. what are you playing on? I assume that you're playing on a console since you asked about TVs. If your setup is on a desk then I would suggest a 27 inch 1080p monitor. You don't need any fancy stuff if its on a console since consoles cant use stuff like higher refresh rates (except for newer consoles, but its only 120hz and it's limited to a few games so far), freesync/gsync, or 2k resolutions. If you're gaming on a pc then it depends on what your computer can handle. The ideal setup is a 144hz 2k monitor with gsync, but thats like 800 bucks lmao. You also will not be able to play every single game at 144 fps. It all depends on your specs and what games you plan to play.