sfgiants said:
a) what is the difference between lcd and dlp?
b) any preference? which is better?
c) any good brands? any ones to avoid?
d) any good web sites with info on this topic?
For your first question, the difference is primarilly in the way that the image is created:
http://en.wikipedia.org/wiki/DLP and
http://en.wikipedia.org/wiki/LCD give brief rundowns.
http://en.wikipedia.org/wiki/Comparison_of_display_technology gives a (very) brief comparison of all standards.
When I sold electronics (for Sears, if you must know) I had the opportunity to see many different LCD and DLP televisions, and my general impression is that DLP is better. It really depends more on the quality of the manufacturer though. A crappy manufacturer will make a crappy tv, no matter what technology they use. That said, DLP sets, IMO, tend to be crisper than LCD, especially with motion. Also, DLP sets don't tend to have as big a problem with angled viewing as LCD monitors do, IMO. Again though, high-end LCD screens won't have these problems as much, reducing the difference between the two.
Another big issue is how long they'll last. LCD screens will start to fade after a few years. DLP screens won't have this problem, though you might have to change the bulb. This can be easy or difficult to do, depending on the brand and model, and is something to check out. The bulbs are also expensive, but I never had to replace one, so I can't speak to how much they run for. In my experience, they don't need to be changed so often as to make this a huge issue though. Last I knew, it was something like every 8000 hours, which even if you leave your TV on 24/7 is about once a year.
Avoid low-end brands. When you begin thinking about spending serious money on a television set, it becomes more of an investment, and it's worthwhile to spend as much as you can comfortably afford to get what you want. I'd recommend staying away from the American brands, as they haven't caught up to the Japanese companies at all. What brands you like tends to be a personal thing, tied into what brands you've had experience with in the past, and how well they performed. Personally, I like the Samsung DLPs, though Toshiba makes some nice televisions (both DLP and LCD). I'll freely admit to being a Sony fanboy, but they don't seem to be as interested in the big screen market as others.
One big caveat is that LCD screens actually perform best around 22", which is certainly not the size for a big-screen television. DLP on the other hand works best at 40" and up. Keep this in mind when you're reading reviews - hopefully, a good review will note this. LCD screens lose a lot of brightness and contrast the bigger they get.
Anyway, I hope that's a little bit useful. I don't have any good websites that dissect it in more detail, but a simple google search for the two terms should bring up a wealth of information, especially with regards to comparisons.