Go with 47" (or larger) and plasma if your budget allows.

In the early days of plasma it was possible to have some “burn-in” (correct term is “image retention”). This could occur if you keep an image on the screen too long and a ghost of the image would stay with the display forever. Examples would be permanent images on the screen like corporate logos or icons. In early plasma displays (regardless of size), this was certainly an issue. Now, however, all of the leading manufacturers of plasma TVs – Panasonic, LG, Samsung, Pioneer, and Hitachi – have greatly reduce or completely eliminated any signs of image retention.

According to Jim Palumbo, President of the Plasma Display Coalition (PDC), “New plasma advancements in cell structure and phosphor formulations have virtually eliminated image retention, also known as ghosting. Tests verify that any residual ghosting generally disappeared with normal use after a relatively short time. If you haven’t burned images into your CRT television, there is little chance that you will with plasma. As with any electronic product, you should follow the usage guidelines in your owner’s manual.”

Image retention (burn-in) has been virtually eliminated and is no longer an issue.