I got a new Samsung 42" DLP a few weeks ago. I'm running my PC on it at 1280x720 (I need to get a video card capable of outputting interlaced signals to do 1920x1080), and it looks decent - it's the same horizontal res as a 17" monitor, but I'm sitting back much further, so it balances out. And of course, it does 1080i for my XB360
I got it for $1800 at Best Buy. Well worth it.
Finding a small LCD will be easy. The problem is finding a high-quality, reliable one for cheap. Since you're using it as a TV, you'll want a better contrast ratio (think 2500:1 or better) than PC-specific LCD monitors can afford (normally about 700:1). Good HD LCD is still a tad on the expensive side for the amount of screen you get.
That having been said, if I intended to buy a smaller HDTV,
it'd probably be this.
I feel I should also voice the fact that I would never feel comfortable buying relatively delicate video equipment off of ebay.