DLP sets look awesome if you tend to camp out on the couch and generally watch the set mostly head on. If you tend to watch from more extreme viewing angles, such as working in the kitchen while the set is on in the adjoining room, the viewing experience will suffer. If big is important and viewing angle is not of great concern DLP is the way to go.
Next up is Plasma. Plasma has a nice saturated look and comes in a thin form factor that can easily be mounted on a wall. Plasma is more pricey but has some advantages worth considering. Plasma TVs do not have any viewing angle limitations. Plasma TVs look great from any angle which is one reason they're so popular in bars and other public venues. However, you will pay a premium for plasma compared to the same sized DLP set. Plasma also consume more power and as a result give off considerable amounts of heat.
LCDs were not even a consideration for a big screen environment just a couple of years ago. That has changed and if you've got the bucks offer a very compelling home theatre viewing experience. If you're a gamer we highly recommend the LCD route. The viewing angle with LCD panels is very good, better than DLP but not as good as plasma. Cheaper LCD TVs can cause fatigues and are difficult to watch over long periods of time. We prefer DLP but this is very subjective. You can't go cheap with LCD. The Sharp AQUOUS line is a good place to start when checking out LCD flat panels.