I recently finished an exhaustive month of doing intensive research on what kind of big screen TV or home theatre system to purchase. I mean, it is time. The tube TV is just not cutting it anymore, especially with a large room where TV is typically watched. I learned a lot in the process ? not all from talking with sales people, but in writing down things the sales people told me, then verifying those facts. The interesting thing is that many times those ?facts? were incorrect, and it made me wonder how many other people were basing a purchase decision on the ?facts?.

For me, the first cut came in considering plasma versus LCD. With projection TV's and even with the DLP technology which appears to deliver an outstanding picture, there were two things that made me eliminate these options in the first cut:

1. The size of the TV. With projection TV's, and also with DLP TV's (although to a slightly lesser extent), size is a consideration. Plan on the unit sticking out from the wall at least 18 to 24 inches, perhaps even more, which severely cuts down the overall size of the room you will be using to watch TV. Plasma and LCD TV's, by contrast, are about 4 to 5 inches thick, and wall mounts can optionally be purchased to actually mount the screen on the wall.

2. The viewing angle. With projection TV, and again to a slightly lesser extent but still present in DLP technology, the clarity of the picture starts to decrease dramatically when you start moving away from viewing the screen head-on. If the room you are going to use to do your TV watching can accommodate this, it may not be as big of a negative point for you, but for me, this was huge.

So my choices are narrowed down to plasma or LCD. Looking at all the choices available in plasma and LCD however, I did not feel that my choices were all that narrow, so I needed more criteria to further narrow my choices.

First cut, let's consider plasma versus LCD and define the technology we want to shop for. I was able to relatively quickly choose LCD over plasma for multiple reasons. With today's technology, plasma screens will typically reach ?half life? within about 5 years. That is the point where the screen brightness is about half of what it was when it was new. By contrast, LCD life expectancy is about twice that, so this was a definite factor.

Your criteria may vary for other reasons though. For example, today's consumer LCD TV's max out at around 46 inches. This was fine for me, since a larger TV would almost overwhelm the room I will be using, but with LCD, be aware that you are not going to get the 50 or 60 inch units that are available in the plasma lineup.

Although I live pretty much at sea level, also note that if I ever anticipate moving to a high altitude area, most plasma manufacturers will not warranty plasma units at more than about 5000 feet above sea level. Really! This has to do with the way the air movements happen to create the picture, and this cannot be done as effectively at higher altitudes. This is not a factor for LCD technology.

Next is the resolution. I recommend a resolution of at least 1366 by 768 pixels. That is even more than today's cable companies broadcast at, but should keep you in line with the broadcast technology over the next few years. Even the movies you rent at Blockbuster are not going to show up in higher resolution than that. There are some top end units (Samsung and Sony, as well as others) that have 1920 by 1024 resolution, but the reality of it is that you will end up paying a premium for that higher resolution, and the ONLY way you will ever be able to use it is connecting your computer to your TV. That resolution will NOT be used for DVD movies or broadcast, or even HDTV broadcast, it is simply not there. So in essence, you are going to be paying for bragging rights, and those are some pretty expensive bragging rights.

Get something that is at least 1080i and 720p. The ?i? indicates ?interlaced? and the ?p? indicates ?progressive? scan. While cable TV broadcasts may do 720p, some units can interpolate that to 1080i. Again, you will pay a premium if you opt for a unit that can do 1080p, and again, that is for bragging rights only. Even a video professional with a microscope would be hard-pressed to differentiate between 1080i and 1080p with today's movies or cable TV broadcasts.

Considering all the criteria above, this should narrow your choices to less than a half dozen units. So your last step is to search online for reviews. See what other customers think of the unit and read their online comments. While I am not necessarily a big fan of paying for a specific brand name for the sake of it being a brand name, there is also some wisdom associated with that.

Lastly, as opposed to many other things, I would recommend the store's extended warranty. If you elect to go with just the manufacturer's warranty, note that you will need to keep the original box that it came in, and will need to ship the unit to the manufacturer in case of a problem. That means being without the unit for a minimum of two weeks or more. The in-store warranty from Sears, Best Buy, Circuit City, etc, are usually ONSITE warranties, and typically cover almost any problem, not just something that may be termed a ?manufacturing defect?. This is probably going to add about $12 to $15 per month to the price for a 3 year or 5 year warranty, but when you are spending this kind of money for a consumer electronics device, I believe it makes sense, especially when you consider that if the backlight needs replacing or the unit needs recharging, the parts and labor involved in performing that work if not under warranty are likely to exceed the cost of simply replacing the entire unit.