Size should not be the sole determining factor. I bought a 42" Westinghouse a few years back because the price was right. I replaced it a year and a half later with a 52" Samsung. The Samsung was bigger, obviously, but even if it had been the same size, the level of detail was staggering. It was so much better to look at; there's really no comparison. They're both 1080P, so the pixels are smaller on the Westinghouse, which you'd think would make it seem sharper... but no, not even close. In literally every regard to picture quality (color reproduction and accuracy, geometry, contrast, ghosting, etc.) the Samsung absolutely destroys the cheaper set.
Yeah, you can get a large Westinghouse or Vizio for a few hundred bucks now, but honestly, the picture quality of the high-end brands is so much better that I personally would rather have a much smaller Samsung or Sony than a large Westinghouse (price being equal). I'd do some research, read some reviews and go for a panel which has good quality so that you don't end up unhappy with your purchase. My Samsung is now two and a half years old and I still get people telling me that it's the best looking TV they've seen.
In response to how often it gets used, daily, without fail. We live in a TV heavy house.