If you’ve got a 40 inch TV and are thinking of upgrading to a 50 inch for a better wide-screen cinema effect why not just sit closer. For example, the recommended distance for viewing a 50 inch screen is 1.8m which is a viewing angle of 34 degrees but if you sit just 35cm closer to your 40 inch screen (1.45m) you will get the same result without having to spend any money!
For a 32 inch screen sit 1.15m away for the same result
For a 26 inch screen – sit 0.95m away for the same result
I think 1.5m is about as close as you can comfortably watch a TV from a settee so a 40 inch is about right for little me! You only need a bigger one if you’re going to invite all the neighbours round to watch football matches! Lol