*What is the difference between LCD, LED, and Plasma? Plasma seems a lot less expensive, and LED is the most expensive. LCD is right in the middle on cost. What is the difference and benefits of the 3 types?
Actually there are 4 types of TVs you can now buy. LCD, LED, Plasma and DLP.
LCD and
LED both work the same way, You have a panel of liquid crystals that bascially acts as a changeable filter turning specific pixels on the screen on or off (letting light pass through or holding it back)... the LCD uses florescent tubes to provide the light from behind the screen while a LED uses a light emitting diode to provide the light... LCDs usually use 2 or more of those florescent tubes, the tubes are bit like the ones in an overhead light and will eventually burn out, when it happens they may or may not be replaceable by you... most aren't and would require a TV repair service to fix it. The LED on the other hand will likely last longer than any other part in the TV... LEDs rarely burn out. The only down side to an LED is that some are a bit too bright in a darkly light room, they do however use the least amount of power.
In both LCD and LED you have only one real issue when you get the TV, Dead pixels, little pixels on the TV that might be dark or light regardless of the picture you are watching... caused by a defect on the liquid crystal panel that doesn't let the pixel turn on and off as it should. This is an issue because they can be very annoying especially if they are near the dead center of the picture. This is also the one reason to be very careful where you buy the TV. Most manufacturers WILL NOT replace a TV because of dead pixels. Most manufacturers claim that a certain number are too be expected and are not a defect (regardless of the fact that you paid a couple of thousand for the TV).... the best defense you have is to buy it from a place that will exchange it or refund your money without questions or without a restocking fee.
Walmart and Sams are my favorite places because it is easy to return the TV and not get hammered with a restocking fee. Always look at the fine print on returns, if I'm not mistaken
Best Buy will hit you with a fee if you return a TV, other places certainly will so make sure you know the return policy before you buy.
Plasma - works close to the same way as your current CRT TV. The panel is made of little lights that will light up to create your picture... big down side is that plasma TV don't last forever and over time they will become more dim. They also use more electricity than any other type of TV your looking at. Are also heavier than a LCD,LED (not much but some). The benefit is that they have a very good picture and will give more contrast than any of the other TVs. Don't plan on keeping it forever if you watch a lot of TV plasmas will eventually die and when they do you can't replace any bulb you just throw them away.
DLP - this TV is the cheapest option. It works like a rear projection TV except that instead of different colored bulbs projecting on the screen it has 1 bulb that projects through a spinning color wheel. The upside is the TVs using DLP are cheap and lighter than similar sized LCD/LED/Plasma TVs, they also do a much better job when viewing non-HD content. The downside is that they do require a special bulb which burns out after a few thousand hours of use (though the bulbs are easily replaced by the user and don't require a technicial to replace, just open a panel on the back pull the old bulb out and slide the new one in). The biggest downside is that they are not flat enough to mount on a wall. A typical 60 inch DLP TV might be 12 inches deep, compared to 2 inches deep for a LED/LCD/Plasma. They don't use as much electricity as a plasma but use more than an LED... They also have the advantage of NOT using a glass screen so unlike the other types of TVs if you kid loses a Wii control and it hits the screen it wont destroy your TV, it might scratch it but will not crack ro shatter it.
*What is a HDMI port, and why do I need them?
*We have a Wii, DVD player, Tivo, and a VCR. Is it going to be possible to connect that many devices to one TV? (We can only connect two right now, and have to swap them out when needed.)
HDMI ports are special ports that allow you to connect one cable from a device to the TV so that both the audio and video signal use the same cable instead of having to connect individual audio and video cables... the stores will overcharge you for these cables, I've seen store charge over $100 for a HDMI cable that is no better than a $10 cable. I order all my HDMI cables from a place called monoprice.com, the last time I checked a 6 ft HDMI cable in your choice of colors cost about $4. DON'T overpay for cables.
As for what you need, I have no idea what type of output ports your have available on your listed equipment except the Wii (it doesn't have an HDMI option only component and composite video).... I'm guessing the DVD might have an HDMI option but it depends on the age of the player. The VCR is unlikely to have the HDMI. The Tivo I'm unsure of. Your problem will be finding a TV that includes enough component and composite video connection for you to hook up all your equipment.
you listed 4 items that probably don't have HDMI connections and almost all TVs are now moving toward having multiple HDMI connections and only 1 or 2 component/composite connections. I assume you could simply use your Tivo and VCR with a coax cable and turn to channel 3, but you will likely only have one coax connection so you would be having to daisy chain those two and probably don't want to have to disconnect and reconnect the Wii and DVD player all the time... so look carefully at the number of composite and component connections... you should be able to find TVs with at least 2 and if you get lucky might find some with as many as 3... but most will be heavier on the HDMI side.
*What is a refresh rate? Why is it important?
refresh rate is really not that important at this point, it is really more of a marketing gimmick unless you plan on getting a 3D capable TV. The reason is that source material you are going to display is at most a series of 60 images that will be sent to your TV per second... a good deal of your content when you watch a movie is only 24 frames per second (fps)... so when a TV has 120 Hz (which means it refreshes the image 120 times a second)... what that means is the TV getting a TV show made of of 60 fps will show frame 1 twice before showing frame 2 twice before showing frame 3 twice and so on... or in some cases the TV will use special software to take frame 1 and frame 2 and create what it believes the frame in between should be, so in this TV the real images would be 1, 3, 5, 7... and so on... and the ones the TV generated as filler would be images 2,4,6,8 and so on... If you get a higher end TV that has a 240hz refresh rate then it is just going to be creating even more of what it thinks is happening than what is really there.... some people like this when watching a sporting even where a ball is moving down field quickly as the TV is pretty good at creating the imaginary frames that the real picture doesn't have... but for most people it just doesn't make sense to pay lots of money for something that isn't really noticable.
*These new TV's have bulbs, right? About how long do they last? When they burn out, how expensive is it to have them replaced?
Summarizing the original overview,
LEDs wont burn out, LCDs will burn out and will require a repair shop to fix usually not worth fixing because of price, Plasmas will burn out and cannot be fixed, and DLP will burn out but is easily fixed by you at home.
A typical LCD repair will cost more than a new TV.... a DLP will cost between 150 and 200 for a bulb (very specialized bulbs).
I've had LCD, LED and DLP TVs.... based on my experience my only mistake was not getting a bigger DLP (ours is 60 inches)... for a movie like experience the DLP is much more like a theater than the LCD or LED.... now if you are looking for a TV to hang on the wall... I would probably go with another LCD, only because the premium for an equal sized LED is still higher than the benefit you get from them... I don't expect to keep my TV forever so I don't worry about the bulb burning out... for the record our oldest LCD TV is about 7 years old and the bulb hasn't burned out.