There is no definitve answer as to whether a plasma or LCD panel gives the best picture.
They're both capable of excellent results. They are simply different to each other.
An LCD can be much brighter and it's pictures, subjectively, pack more punch than a plasma, it also doesn't suffer from screen burn whcih can happen top a lasma if it's operated with stationary images on too high a contrast setting.
Conversely it is more lkely to exhibit smearing with fast moving objects and (particualrly on the lower specified models) may struggle to resolve picture details in dark and shadowy areas. Also backlight leakage is not unheard of on certain models and the viewing angle is (theoretically) less than aplasma..
A plasma will give a more restrained (some would argue more natural) picture with little motion smear and bags of shadow detail.
Conversely there is the screen burn issue detailed above and poorly specified sets may exhibit grain and fizz over moving objects.
You will find many supporters of both technologies.
All anyone can advise is to audition a range of sets and make your own decision based on what you like, possibly, if you have friends with both technologies look under normal lounge lighting rather than harsh shop lighting.