There are a lot of variables when picking a TV. If your looking for some super advice on TV's head over to "https://www.highdefforum.com/" they helped me pick my last TV.
I can give you some advice too.
Yes. LED just refers to the backlight technology. LCD's and LED's both use the same technology to render the picture, just different lighting techniques behind it.
In regards to power consumption it goes LED, LCD, Plasma. Plamsa uses the most electricity.
In regards to quality of picture it goes LCD, LED, Plasma. Plasma produces the best picture.
In regards to price it goes LCD/Plasma, LED. LED costs the most.
As far as life expectancy goes it varies. The brand name plays a big role in how long you want your TV to last. Here is a good guide on brand names
https://www.highdefforum.com/flat-panel-tvs/57224-flat-panel-buyers-guide-noobs.html Before you go and try to find a TV you need to decide how BIG a TV you want/need. This calculator is a good place to start. It takes all factors into play including your eyesight!. What good is a high def TV if you can't decern the difference between 1080p and 720p?
https://myhometheater.homestead.com/viewingdistancecalculator.html I bought a 40" LCD 1080p samsung last year. In hindsight I wish I bought the similarly price Plasma. LCD's just don't give the picture quality that a plasma can deliver. A LED TV can proboably match a plasma in quality, but definitly not in price. Even with power consumption taken into account I would prefer the Plasma at this point in time.
