flat panel LCD's are brighter, lighter, thinner, more energy efficient, don't have glare, can work at any altitude, have awesome viewing angles etc etc. but tend to not have as good of color as Plasma and on lower res video signals look a little more distorted.
plasmas have great color and viewing angle, good brightness, and come in big sizes. 42" is about where they LCD's and Plasma's intersect in price with larger LCD's being more money than larger Plasma's. If you have a room with windows or is a generally bright room, LCD is probably the way to go. LG makes a nice mid-level LCD and plasma while the higher end LCD's from Sony (kdl40xbr2) and Samsung (lns4095w) are super bitchen but get up over 3g's pretty quick.
ED tv's are only capable of 480p resolution--so the max resolution of DVD. HD programming is 720p/1080i and will eventually be 1080P (P is better than I--thats all you need to worry about ). Blue Ray disk players and the Sony PS3 are capable of 1080P resolution, so if you think you are going to be stepping up to a newer technology game system or video player you may want to consider stepping up to, at the very least, an HD TV or even bettter a tv that is a full 1080P resolution.
http://www.circuitcity.com/ssm/Shar...61576/catOid/-12869/rpem/ccd/productDetail.do
This is the cheapest 1080 P LCD and it's as 42". I just got the 46" one up and it's a great looking TV, although the color isn't nearly as nice as the Sony stuff that is 30% more $$$. Still a really nice tv for 2000 and if you buy the PS3 it'll look uber bitchen.
If you're not worried about HD programming and just want a big flat panel to put on a wall or something try this
http://www.circuitcity.com/ssm/Sams...47581/catOid/-12869/rpem/ccd/productDetail.do
anyways, hope that helps.