The DLP's systems from Samsung have problems with the 'rainbow' effect, so they are not a good choice. The effect occurs when light hits the edge of the micromirrors in the chip and defracts.
It is pretty prevalent in the DLP sets I have seen. I am sure it will get worked out though and has promise.
LCD is ok, but color and contrast are normally mutually exclusive and more often then not they are a bit washed out or just flat wring in the color representation.
The high end plasma sets have the best picture of any set, bar none. But expect to pay over $15,000 for them still. They are still not proven for longevity. It is known that each year you can expect some of the pixels to die.
The rear projection sets are pretty good. Much better than they used to be, but the best guns you can find are all 7 inch, which was fine for NTSC/PAL, but the guns are not going to hold up to the HD resolutions for long. They really needed 9 inch.
Back to the old CRT. Longevity, proven technology, inexpensive and pretty nice looking.
----
That is a general summation about the technology. Who makes the best set is up for grabs and everyone will have an opinion.
For rear projection, I would lean towards Pioneer Elite.
For CRT, all I have ever owned were Sony XBR2 sets. I would not buy the regular Sony stuff, but I have never had a problem with any XBR2 set.
Consider this as well. If you like DVD, and might be thinking about HD-DVD (which ever format wins), you might want to make sure your set has an HDMI connector on it, as it appears it could be the interface of choice for HD-DVD players (regardless of format).