A big TV that's too close can be just as uncomfortable to watch as a small one that's too far away, so don't assume that the biggest screen available is the best choice. There are a few different rules of thumb regarding TV screen size based on your distance from it.

Generally, the distance between your couch and your TV should be between 1.2 and 1.6 times the diagonal measurement of your screen. So if your couch is six feet away from your screen, you can comfortably watch a TV between 42 and 60 inches. If your couch is five feet away, a 37- to 52-inch screen should work well.

For more, see our stories on how to choose the right TV screen size, the best 65-inch TVs, and the best 75-inch (and up) TVs.

Ideally, a TV should provide enough video connections for now and the foreseeable future. The most important input is HDMI, which supports all major forms of digital video sources, including Blu-ray players, game consoles, set-top boxes, and PCs through a single cable. Most TVs have three or four HDMI ports, but some might only have two. If you want a 4K screen, make sure the HDMI ports are at least HDMI 2.0. It's the current standard and supports 4K video at 60 frames per second; at best, older HDMI ports can only handle 4K up to 30 frames per second. HDMI 2.1, meanwhile, supports higher resolutions and faster refresh rates, though it isn't vital for most content currently available.

As for cables, unless you have a huge home theater system and plan to run cables between devices at distances longer than 25 feet (and that's being generous), brands and prices don't matter. We've compared the performance of high-end cables and inexpensive ones and found that they all carry digital signals similarly. More expensive cables might have better build quality, but you won't see any performance advantages from them. Don't shop for HDMI cables at retail stores, and ignore any clerks who warn you of "dirty electricity" or "viruses" that can come with cheap cables (both claims I've witnessed). Hop online and find the least expensive cable at the size you need and snap it up.

Just ensure the cables are labeled HDMI 2.1, "Premium High Speed," or "Ultra High Speed." For more, see our story on what you need to know about HDMI cables.

HDMI also supports the highest-end home theater audio standards, though you'll generally have to give up a port as a video input to use it. Most TVs have an HDMI port with an audio return channel (ARC) clearly labeled on the back. ARC enables sound to be sent downstream to a connected soundbar or speaker system from the TV over HDMI and supports compressed 5.1-channel surround sound, like optical connections do. However, recent TVs have enhanced ARC, or eARC, which offers even higher-quality audio and more features than optical or ARC can provide. eARC supports uncompressed multi-channel sound, including spatial audio like Dolby Atmos and DTS:X. In fact, if you want to use those much more precise surround systems instead of discrete channel feeds, you need to use eARC.

If you have legacy devices from before the days of HDTVs, some new TVs might still support them. While they're not standard, many TVs have composite or component video inputs you can use to hook up VCRs and older game systems. Groups of full-sized RCA ports might be available, but you're more likely to find 3.5mm ports designed for use with included dongles that convert the 3.5mm connection to three RCA ports for composite video or five RCA ports for component video.

Keep an eye out for sales around big sporting events like the Super Bowl or when football season is just starting to find price cuts of a few hundred dollars or more. Also, expect huge price slashes on budget and midrange televisions during Amazon Prime Day and Black Friday. Note that manufacturers typically announce new TVs in January and mark down the previous year's models around that time. Regardless of when you shop, pay attention to which models are on sale; different tiers and series of TVs can perform wildly differently, and some budget and midrange lines aren't nearly as good as higher-end models. Check the model numbers carefully against reviews for a good sense of whether the discount you see is worthwhile.