I'm trying to decide on what to get for new TV myself, although I'm gonna wait a few months until all companies announced their 2011 models. And then I will probably another few months for reviews and then a few more months for the prices to drop a bit. So I guess I buy my new TV in september or so
LCDs have a slight delay (not that I've noticed), so make sure you get at least 100 Hz.
LEDs are the best, just whether you can afford it.
All flat TVs suffer from the delay (AKA input lag), including plasma. So it's not exclusive to LCD. Among the 2009 and 2010 models it seems like Panasonic (plasma), Sharp (LCD) and Philips (LCD) have the lowest input lag. Samsung and Sony are not that good from an input lag point of view.
100Hz will not help against input lag in any way. It's more about how fast the TV convert the signal into the same resolution as the TV and adding various filters to "improve" the image.
"LED" TV (which is still a LCD TV but with LED backlightning instead of CCFL backlightning) can be great or awful depending on what technology is used. For example, many Samsung LCD LED TVs use edge-lit LED, which is absolutely horrible from an image quality point of view and give lots of clouding. However, the benefit of edge-lit LED is that they can make the TV very very thin, and for many the looks of the TV seem to matter more than the quality of the screen. Strange.
The reason isaid no plasma before is becuse they tend to have images burn into them after a period of time.So things like the HUD in video games can get stuck on your screen.
That's not really up to date information any longer. It's very hard to burn a modern Plasma-TV. For most people Plasma would probably be a better choice.