I think it is down ultimately to preference and what you want out of the TV, I have purchased (Delivery on Tuesday) of the Samsung UE55c8000 for two main reasons:
Samsung seem to be struggling at present with their Plasma's in that once 3D content has been played, you get visible bars for quite a while during other content, I wouldn't touch the LG currently, although the Sony one is currently receiving very good reports.
Now down to the two reasons:
I have compared Panasonic Plasma directly to the LED Samsung and must say the LED is far more vibrant and noticible although the plasma content was good, the LED is the leader.
I have just purchased my Samsung UE55C8000, the 3D blu ray player C6900 and the 3D kit with two pairs of glasses and 3D blue ray move including delivery for only £2610 all in. So there are bargains to be had providing you know where to go for them, If you choose the Samsung route, then I would be more than happy to give you the details of my purchase, oh and for the price they also threw in 5 yr warranty on the TV, my delivery comes this Tuesday and all being well, I will provide the details to you.
Upon talking with my supplier the Samsung responds extremely well to the PS3 3D content currently available with no lag and vibrant 3D pictures.
choose well, but dont go anywhere near the LG, for me your choice is Samsung or Sony, having extensively researched my purchase, I am still happy with the Samsung.
Good luck with your decision making.