Depends upon how much money you have. I've had no money for the last year+ so I've just spent it researching TVs
I'd pass on Plasma right now. They've vastly improved but the weight/size issues don't make them as flexible for arranging-rearranging.
DLPs are on the way out. There are only, I believe, two manufacturers left. That being said, DLPs with the new LED color wheel (from Samsung) are great. No more worrying about replacing the bulb every couple of years, very true black and the newest ones are the greenest/most energy efficient/cheapest out there.
If you do go the LCD route, look at the Samsung LED LCDs. Again, somewhat costly but they provide the truest black you can get in an LCD.
There's always the Sony's as well though they usually cost a small fortune.
And don't forget that Mitsubishi is coming out with a new laser TV very soon (to retail - they've already show cased the unit earlier). A friend of mine is good friends with a lab in town that works very closely with the technology. Apparently they had to fuzzy it up because the color and detail accuracy were so good that it looked unnatural to people watching it. I can't verify as I haven't seen it.