LCD is the oldest of the three technologies (we aren't considering CRT's for obvious reasons) and also the most mature. Comparatively, Plasma and Projection TV technology are in different stages of evolution.
LCD monitors & televisions work great for gaming, movies and general entertainment. They are more mainstream and the affordable price points mean more people can buy them with ease. Common sizes range from 21-32" and more.
Plasma TV technology works great for movies because of the high contrast and smooth transitions they are capable of. High definition movies are fun to watch on a plasma tv. Common sizes range from 32-47" and more.
Projection technology is about living life king size. Rear projection TV's come in mammoth sizes of 50" and above. It is not uncommon to find a 60" projection TV in the family living room.
