It's unfortunate most of you guys cannot provide decent advice on electronics. The OP would be much better off asking the same question on AVS forum.
The real answer: it depends on your situation. First, what is your viewing distance? Second, what is your budget? Third, what kind of content will you be watching (ie xx% SDTV, xx% DVDs, xx% HDTV, etc.)
Some guys here would tell you a HDTV is always better than an EDTV, which is entirely wrong. Try comparing something like a $2000 42" Maxent HDTV plasma at Best Buy versus a $1700 42" Panasonic EDTV plasma, and the Panasonic will win hands down, even when displaying HDTV signals (which they both can do).
Why does viewing distance matter? Plasma screens have pixels, and if you are too close to a screen you will see the tiny lines between the pixels. This is called the Screen Door Effect (SDE). HDTV plasmas have smaller pixels than EDTV plasmas, so for shorter viewing distances I would recommend an HDTV plasma. For farther distances, SDE will be unnoticable on either screen.
Why does your budget matter? If you have a hard limit of ~$1600, then the smart decision would be to buy a excellent EDTV set. *IF* you can find a great HDTV set for the same price (for example, Costco had great deals on Vizio HDTV plasmas for around that price), go for it. But don't simply get a HDTV without reading the reviews first. There are a lot of crap plasma sets out there that simply cannot compete with a Panasonic EDTV plasma in terms of contrast ratio, brightness, black levels, and accurate colors.
Why does what you watch matter? Well if 90% of your viewing is going to be SDTV and DVDs, why fret over having an HDTV? Sure, maybe in the future you will start watching more and more HDTV, but a good EDTV set will still display HDTV signals with excellent quality (read reviews on Panasonic EDTVs anywhere online; most owners rave about the quality).