Well, first I think you need to decide upon what size screen do you want, and do you want widescreen. This might eliminate direct view CRTs. Also, how much do you want to spend? Setting a limit of say, $2,000, will eliminate plasmas and direct view LCDs, for the most part.
Then decide if you are OK with a dying technology and you & your SO are willing to put up with a very large, heavy TV. There are other concerns, but let's not go into detail here. If you MIGHT want a CRT RPTV, go look at a Mits with 9" guns. I was not impressed, especially with limited viewing angles. Others ARE impressed. If you do not care for that TV, no need to look at any other CRT RPTV, they are all lesser creatures. If you are happy with that, it will be on the cheap end of your options. Just factor in paying for professional calibration once installed. Don't worry too much about burn in, unless you're a gamer or otherwise leave static images on screen for hours at a time.
BTW, IIRC, the industry considers CRTs of all stripes to have reached the end of their useful lives when they decline to half brightness, after about 5-7 years. I have direct view CRTs much older than that, that I am happy with. Go figure.
Organic LCDs had lifespan problems. Newer, inorganic based LCDs are much more trouble free, and do not have image persistence problems, unless you leave a static image on for days. Even then, they will likely recover over a few more days. The latest LCDs do not leave "ghost trails" as much as earlier ones did. Yes, there is some aging and fade, but this is not really a big worry. CRTs will age faster. Black levels are not the best, but most people are happy. I haven't heard of a pixel burning out in years. Just check for that when you first get it, in case you get a defect. Direct view LCDs will have backlights. Some are replaceable by the user, some must go in the shop, some you might as well replace when they dim too much. The new LED backlit LCDs will last longer than you are likely to keep the set, with little dimming. Most folks will never bother to replace the backlight- it's gradual, like with CRTs, and you get used to it and don't notice. I'd guess if you were looking at the 40" range or so, this is a candidate. Above 50", forget direct view LCD.
At 50" or above, the LCD RPTV is a candidate. Once a bulb dims/dies, you pop in a new one, and the TV looks literally as good as new (same for DLP & LCoS). Fill factor is not as high as CRT, DLP or LCoS, but is better than plasma. And maybe a bit better than direct view LCD. Think "screen door effect."
Plasmas, at least from name brands and of recent vintage, have acceptable blacks and display motion and color better than LCDs. But not tremendously better. They are heavier and use a bit more power. They generate heat. They emit noise at higher altitudes. Their fill factor is not so good, since they are made up of many tiny glass tubes. They have great viewing angles. They use phosphors, just like CRTs. Burn in and life span on a modern plasma are not big problems, unless you're a negligent gamer. But it does dim over time. You will not "recharge" or do anything to renew a plasma TV. You'll replace it. But again, this would likely be after many years of home use. Figure 42" to 60", roughly. I believe plasma sales will continue to increase, but will eventually top out and decline. I don't see them being a big part of the market 10 or 15 years from now- fill factor problems and they just won't keep cutting their costs to compete with other technologies. More expensive than LCD.
DLP. Lots of mirrors. Roughly 46" to 70". Most use color wheels, which are a source of trouble. New ones that avoid the use of color wheels, and their problems (rainbows, headaches) are coming out. Mirrors can only be so close, so there are some fill factor concerns. Not a biggie, though. Popular. RPTV only. Eventually, I believe RPTVs will disappear, replaced by thin screen technologies. But then, in the long run, we are all dead.
LCoS. This mostly means the JVC D-ILA and the Sony SXRDs. JVC seems to have had more success here. These are reflective technologies, like DLP. Pretty much the whole face of the chip is covered with imaging material. For LCD RPTVs, the light shines thru the chip, so the circuitry- wires and transistors - surround the image forming material, creating some screen door effect. For LCoS, the wires and circuits are behind the imaging material, producing the highest fill factors. Fast response time. Available from roughly 50" to 70".
SED. Unlikely to ever see mass production. Samsung may take over from Canon in pushing this technology, but lawsuits have delayed this so long it is unlikely to ever be able to be cost competitive. Might still have problems, like emitter erosion or uneven brightness/aging, as no numbers of units are out for testing or real world use. Likely to be overtaken by other technologies, such as:
OLED. In widespread use today in PDAs and cell phones. Scaling up now, now that lifespan issues have been addressed. Potential of being very cheap to produce, with very high, perhaps the highest, PQ. Uses almost no power. Emits light, so it needs no backlighting or bulb. Kodak has stated their intention to put an OLED TV on the market in 2008.
There are more issues and aspects to consider, but I don't want to write a book here.
The technology is changing so fast, you might want to go on the cheap end, and just plan on an earlier replacement. And count on whatever you buy being outdone by something cheaper and better a year later. This is not the time to buy a $10,000 TV.
