I thought about going for 240hz refresh last year when we were shopping, but the price differential wasn’t worth it for us. I gather if we watched a lot of sports, or played a lot of video games, it might have been. We wound up with 120hz which seemed a good compromise. Depending on what you’re replacing, even 60 hz might be a huge improvement (we were replacing a 1991-era 19 inch Sony!!).
LED-lit LCD TVs are thinner and use even less energy than regular LCD TVs, but there’s a cost differential. I wanted the LED for the energy/environmental impact but that may not be essential for you.
Plasma vs LCD: Plasma uses more energy but has a wider viewing angle and more glare. They all looked fine to us in the store so we went with LCD. And yeah, if you’re off to the side it’s not perfect but it’s still pretty nice.
Consider a smart TV - i.e. one that can get content from the internet. Typically you’ll find that they can get content from Netflix, Amazon or both (plus other sources like Youtube, Hulu etc.). I have been surprised at how much we’ve taken advantage of this. Sometimes you can get that feature in the blu-ray player instead (the one we got accesses just Netflix, I think). I’d bet pretty much any TV, aside from the cheapest ones, will have at least some smart capabilities.
Wireless can be useful if you have a wireless router, that will let you access the internet-based content. What we found, however, was that we’d get about 2 minutes into a movie and it would freeze and I’d have to reconfigure the TV’s wireless settings, lather rinse repeat. Since our internet and TV come from the same company (Fios), there’s a coaxial outlet right by the TV; I wound up purchasing a MoCa (I think) adapter and cable splitter so I could send a wired signal to the TV. Other providers such as Cox use a standard cable modem that you can purchase anywhere, I had to order our adapter online. Much more reliable than the wireless, once I got it set up.
In any case, consider your internet provider and how to get that signal to the TV, it may not change which one you get but it will help in deciding what extras you may need (like our MoCa adapter).
HDMI inputs: Our TV has 4. I think we’re using two right now: one from the cable box, and one from the BluRay player. A gaming system might use a third (we have a Wii which does not do HDMI input). Other peripherals might use a fourth. Lower-rent TVs might only come with 1-2 HDMI input slots, I’d recommend looking for 3 or 4 instead.
Despite what the gentlemen tell us, size DOES matter. Get the biggest TV that fits your budget and your room. If you want to get a visual for how big that would look in the room, take some newspaper or something and make a shape of the appropriate size, and tape that up on the wall and look at it for a few minutes. We have a poster in the same room that was pretty close in size, so that gave us a visual - and I still wish we’d gone a bit larger. We have a 47 incher and a 52 or 55 incher wouldn’t have been out of line.