Where are you putting the TV?
One major question that people leave out when looking for either plasma or LCD is the room environment. If you take two equally good tvs, one plasma, one LCD and set them up in a room with lots of ambiant light (bay windows, accent lighting, or bright lights of any kind) on the same signal, the LCD would look better due to it design of a matt finish for the screen. Plasma has a sheet of glass over the screen that will reflect a LOT of light and diminish that coveted contrast ratio. Likewise, if you were to move those same two tvs into the basement with low light (or no light), the plasma will look better as it can achieve better black levels and usually handle motion and colour reproduction better. Take a look at where you will put the set and see what technology would work better for your application.
With that being said, I would have seconded the motion toward the Sony V2500 (almost XBR specs for Hundreds of dollars cheaper) when it comes to LCD, but 2 days ago at work we recieved the brand new Sharp pannels. All I can say is WOW!!!!!!! Puts the XBRs and Samsung sets to SHAME. Sharp definately has made a move to take back the LCD market (in the larger sizes at least). I have never seen such detailed, black levels on an LCD... ever. Take a look at it before dropping any cash. That TV has moved to the top of my "must have" list. Its the LC42D62U (available in 42", 46" and 52".... the 52" is hundreds less than the 46" XBR2 and I think that it looks much nicer).