It used to be that buying a TV meant choosing from a relatively small range of sizes, with one of the biggest questions being if the TV set had a remote control. Occasionally you'd see someone get fancy and buy one of those combination TV-VCRs.
Buying a TV now is entirely different. Not only is size a factor, but many other features now compete for your attention and wallet. Looking up reviews of HDTVs is a great start, but much of the language can go over your head if you are just now trading in your old analog set and converter box for a true HDTV.
The Option to Turn Off Motion Smoothing
High-definition TVs have a feature called motion smoothing. If you've ever looked at a newer TV playing scenes from a movie that seemed to switch between movie quality and that odd, soap-opera-ish type of film, that's an effect of motion smoothing. It can be annoying to many and make films look like they were filmed for television in the 1970s. Be sure the TV you get has the option to turn off motion smoothing so picture quality is more consistent.
HDTV or UHDTV?
Not only do you have a bunch of HDTV variants to choose from, but now you have UHDTV (ultra-high-definition TV), also called 4k. This uses a technology that's more similar to IMAX films, and it brings all the clear resolution that you'd expect -- but it also brings the drawbacks, too, such as the potential for making some viewers feel nauseous if the image isn't very stable. When you read reviews of UHDTVs, look specifically for signs that the model may be less likely to have these adverse side effects.
Screen size still plays a role, and not just because you may have a general preference for larger screens or need a smaller TV for the kitchen. The screen size affects resolution. Smaller screens may be too small for super-high resolution, such as that in UHDTV; the screens are simply inadequate and won't really show the high resolution after a certain point. Larger screens may be ill-suited to lower resolutions simply because the low resolution is going to be more apparent when the picture has that much room to play in.
You should take your time with this purchase. Smaller HDTVs aren't that expensive anymore, but larger ones are still pricey, and this is spending that you want to do wisely. To learn more about HDTVs, read HDTV reviews online.