Before you even begin to look at TVs you need to consider where it's going. While it may be cool to keep a 58-incher in your bathroom, unless you have quite a large bathroom it may get hard to reach the sink. A piece of cardboard cut to the size you'd like is a good place to start. Try taping it where the TV will go and get a feel for how it fits in the room. Also keep in mind that you likely need a larger TV than you think. To see the detail you've paid for you should try and keep a 1.5 times ratio of screen size to viewing distance. Size is arguably the most important factor after you've settled on what really determines which TV you purchase: budget.
Setting a budget before you start looking is key. It will help you sift through the features you need and those that would be really awesome if you only owned six other devices and had a soundproof room to keep them in. You can spend anywhere from $300 to $8000+ on an HDTV. A budget makes sense of the other numbers.
With budget and size in hand you should begin to think about other features. Getting in the store and testing them out is the best way to determine what's right for you. And if the salespeople want to make a sale they'll put a remote in your hand. Here's a list of the important factors:
This is the most important part of the visual experience of a TV. Most televisions can produce a true rendition of white with ease. It's the true blacks and the transition from black to white that separate good from great. Go to a scene with a lot of black, cup your hands around a dark section and look closely. Is it truly black or is it glowing? Move from black to white. Is it a smooth transition? The tag will likely have some ridiculous number like 1,000,000:1 dynamic range. This was simply chosen by the manufacturer, but can't be used for comparison. There's not even a standardized way to measure the contrast ratio. Just stick to what your eyes tell you.
2. Viewing angle
Stand in the middle of the tv. Now move right or left slowly. At what point do the colors start to look funny and unsaturated? That's the edge of your viewing angle. Now think to where people will be sitting in front of the TV. Is this edge acceptable for where people are going to watch? Depending on where you're using this TV the vertical angle can be important too. If you plan on looking down or up at this tv, try crouching or standing on your tip toes to see where good color representation ends.
3.Static and motion resolution
This is a fancy term for how crisp things are. Can you make out the individual hairs on a person's head? Good. Motion resolution can be a consideration if you like sports or action movies. But most people can't detect the difference in blurring of a player's legs (a common test of this factor) at 60 or 600Hz, and the technology that produces higher refresh rates can some movies and tv shows look bad. If you're really concerned about refresh rate try a plasma, they don't usually suffer these issues.
4. Your gut
Do you like it? Really, really like it? Because that, more than anything, determines your experience with a TV. Terms and reviews can give you direction, but everyone is different so choose a TV you love above what you read in a review.
In the next post we'll look at a few more technical terms along with things that don't matter (but what they'll try to sell you on anyway).