Plasma just has all around better image quality. Deeper, inkier blacks. Smoother, more natural looking motion. And the old drawbacks of plasma tech (burn in, image retention, power consumption) have been largely improved. Not to mention they are usually cheaper than comparable LED TVs.
However, if you are going to use it as your PC monitor I would still consider going the LED route. It is the only time I will suggest LED over plasma. I think the risk of burn in would be more so when using it for a PC. Although, if you are careful about not leaving static images on screen for too long (like your desktop) you might be OK.