That entirely depends on your needs, and unfortunately, there is no single answer to the question. I could try going for the safe middle ground and suggest you to buy a 42″ Samsung TV, but then you’d be disappointed in case your living room is larger than the average. You’d also be left with second thoughts if it’s not something you can afford, or even need for your single bed bedroom. Some further exploration of the topic is whole-heartedly recommended.
How many times have you thought you could use a bigger TV than what you have now? If the answer to this question is more than none, you probably have an idea already. It’s still not the best and most wallet-friendly idea to go and pick the biggest flat-screen TV from the shelves of your local store. As mentioned earlier, a 42″ one would be a safe bet to be put into any room bigger than 8 by 10 feet.
Of course, since there is no one-size fits all, it’s probably a good idea to set a baseline for those who don’t know what to look in a “small” big screen television. The smallest one I would go for under any circumstances is 32″, but not because I couldn’t survive with something smaller than that in my room. The reason behind this lower limit is resolution. Screen resolution decides how fine the picture will look like given that you feed it with the content it requires to operate at native resolution.
Under no circumstances would I give money for something less than full-HD now, 1920 by 1080 is the least a television should know, even if I wouldn’t have the technology to put content of this resolution on screen. It gives space for further improvements in your playback devices, such as a blu-ray player, or a laptop with an external display port. The price difference is so little between 1366 by 768 (often dubbed HD-ready, giving it the erroneous feel that it has something to do with high definition; no, it doesn’t) and full HD that opting for the former could only happen when you aren’t familiar with the differences between full hd and hd ready.
A good way to get the optimal screen-size would be to look at your room and see what size it is that you can fit comfortably. Whip out a scale and do an estimation, see if 40″ would be enough or you need to go all the way up to 46-52 or even 60 inches. Once you have the maximum screen size your room can accommodate, go virtual shopping in online stores, so that you have a basic ‘feel’ about prices. See what can your wallet handle, and look at the resolution your chosen display offers. Try to opt for more than just one HDMI input, because you never know when will you have to connect another source of content, such as a console, or a computer.
However fond I am of the current Samsung LED TV lineup, I can’t recommend them if you need a television bigger than about 55 inches; simply because manufacturers can’t produce these (and bigger, of course) screens economically. 55 inches diagonal and above is the realm of the plasma technology, which has its own ups and downs. If you’d like to know more about what plasma offers over LED TFTs, use popular search engines to educate yourself on the matter before you run into the altitude issue or other glitches.