If the price was the same, would I be better off with a 42" Panasonic 1080 or a Panasonic 50" 720? I mostly watch sports and DVDs. I will be sitting 12' from the screen. Any suggestions or feedback would be greatly appreciated.
At a distance of 12', it will not matter whether you have 720p or 1080p with either size set:
http://s3.carltonbale.com/resolution_chart.html
And the full article:
http://www.carltonbale.com/2006/11/1080p-does-matter/
Or the same information in a somewhat easier to read chart:
http://www.soundandvisionmag.com/assets/download/0602_tech_talk2_large.jpg
In fact, to see all the detail of a 50" 720p TV, you would have to be slightly closer than 10 feet, and that is assuming you have 20/20 vision.
If I were going to sit 12' from a TV, I would want at least a 60" TV, which would be about the right size to get the full benefit of 720p. In fact, it would be like sitting about 8' from a 42" TV—which is what I do.
Of course, there are other things to consider besides resolution when buying a TV. For example, 720p and 1080p tell you ABSOLUTELY NOTHING about other picture quality issues, such as color accuracy and black levels, or about the quality of video upconversion, or many other matters that can significantly affect picture quality. If I were on a tight budget, I would be happy to settle for a good 720p TV. It is certainly far better than a bad 1080p set.
If you must sit 12' from the set, and if the only differences between the sets are that one is 42" 1080p and the other is 50" 720p, it would be crazy to buy the smaller set. You will not even be able to see all the detail that it can provide at that distance.