LOL DLP TVs can be awesomely good.
Plasma can and does suffer screen burn, several sets at work have gone this way already.
Plasma does sem to have the best picture in terms of colour though, having said that it is also a pretty fragile set to transport. Lay it flat at your peril.
LCD suffers too much dot crawl at present for my liking and isn't as good at the other technologies at fast moving pictures.
DLPTV - cheaper, no dot crawl, no screen burn. Can suffer Rainbow Effect especially on earlier chips and colour wheel hum can be heard on some sets.
It is marginally larger in terms of floor space than a Plasma, not by much though especially if comparing to a floor standing set.
Bulbs can need replacing and can be expensive but will get cheaper as the sets get more popular. I expect ultra bright LEDs to replace bulbs in the near future.
In January last year when I quit smoking I started spending a lot of time looking into the various technologies as my reward for 12 months cig free was to be a large screen TV. To top it off I got a £1500 payout for some photos that I took (most unexpected) in December so decided to take the TV plunge.
I opted for the Sagem 50 inch DLP RPTV on the Texas Instruments G4 chip. Had the TV 2 months now. Love it. Love it with my 360. Love it with my Xbox. Love it with my DVD player (upscaling Samsung HD950).
Viewing angles seem fine to me although I rarely stand off to the side of the TV in order to look down on it and across at it. Judge the TV on how it is going ot be viewed.
If you have a weird living room and often watch the TV at 45 degrees from 2 feet above it then make sure you pick a TV that looks good like that. I don't so I want one that looks good sitting on a sofa 10-15 feet away square on at a normal viewing height.
I think theres a lot of snobbery over the technologies at the moment, I also think Plasma has the best overall picture but at quite a price. I could get 2 of my DLP RPTV for the price of a really decent plasma. I know which is better value.
Check out DLP.com for a nice explanation of how it all works, it'll explain why it doesn't have any refresh rate issues unlike LCD for example.