Ok let me see what help I can give. First, 1080p is the best you can get, it is going to be the standard since movies are shot in 1080p. 1080i is just below that. Unfortunately 1080p isn't very common in plasma and lcd yet. If you're willing to look into a DLP then it's easier and cheaper. I've found that DLP is really good with just 2 downsides, first you can't mount it on a wall cause it's not as slim, second the viewing angle isn't as good which isn't a problem if you aren't watching tv at extreme angles.
Another thing to watch out for is make sure the tv has HDMI with HDCP. All tv's should have it now but never hurts to check. The reason I bring this up is the first HDTVs did not have it, and the new HD players will require it, if you don't have it then the player will downscale your Blu-Ray or HD DVD movie to just DVD quality thus defeating the purpose of the player.
Plasma TV's, new ones are getting a lot better. They're about on par with LCD as new technology lets them stay bright longer and the problem of images getting burned in is becoming less of a problem.
My research led me to this, a 56" DLP 1080p tv at circuit city (great viewing angle for a DLP too) was less than $2000. A 46" 1080i (remember, not as good as 1080p) LCD tv at that store and all others I could find in the area was over $2000. Something to consider. But if flat is a must then I'd go for LCD. The DLP I was looking at was a Samsung, I compared it to every other brand Circuit city and Best Buy had and it was easily the best bang for the buck. If you have any other questions let me know. That's the end of my essay.