Sorry for my late reply. The Sony KDL-40W3000 is a superb tv. The only reason I didn't mention it was because I didn't think it was in your price range and I was quite suprised when I checked the various prices available online. Despite what I said about judging each tv on it's own merits and not being hung up on whether it was a plasma or LCD, there is a difference in picture between plasmas and LCDs - I don't mean that one is better than the other, I just mean there are different characteristics in the image that each type of tv displays. It is completely a matter of personal preference as to which image is 'better' for you as an individual person with your own tastes. The differences have to be seen really, as they can only be described to a limited extent. But I will try to explain as best as I can. LCDs pictures tend to be sharper and brighter which is obviously a good thing. This is the reason why LCD panels do a good job as PC monitors. The only drawback with the often superior sharpness that an LCD display offers is that they show up standard-def content, especially poor standard-def content such as many Freeview channels, making such material look pretty ropey. Very ropey, in fact! More importantly, when showing high-def content, although the brightness means that sometimes, movies might not look as 'cinematic' as on a plasma, many people may prefer the extra detail and clarity that an LCD can offer. Having said that, LCDs can blur when displaying fast motion, and this is an area where plasma often beats LCD.
To my eyes, LCD tvs (especially the mentioned Sony KDL-40W3000) seem to have an image that appears to have a kind-of matte texture, while plasma's images (particularly with Pioneer's Kuro range) have a slight 'glossy' look. With colour, LCDs can look slightly washed out, with plasma presenting deeper, more realistic colours. With blacks, plasmas can go pretty deep, while LCDs blackest blacks can look a little grey or even navy blue (a tiny bit). How much this matters is again down to personal preference and your individual taste. Like I have said, it is common for people to prefer plasmas for movies - but again this might not be the case for you.
Like I mentioned before, LCD's razor-like sharpness can bring out the worst in standard-def pics. Plasmas are generally more forgiving, although standard-def is never going to look when blown up to 42" or higher.
I must mention the fact that while I have been talking about LCDs and plasmas, I have often been thinking about the Sony KDL-40W3000 in particular, but as a shining example of LCD's potential, I think this is quite appropriate.
To come to some kind of conclusion, I would just say to reevesey that you should definitely see for yourself the three tvs in action - the Panasonic 42PZ70 plasma, the Pioneer 428XD plasma and of course the Sony 40W3000 LCD, which you may well have guessed that I am a fan of. In fact I am a big fan of all three of these wonderful tvs. Please make sure you have a good look at these tvs 'in the flesh'. And good luck.