No No I am not an expert in this area. As I am also looking for a plasma now I read a lot in this and other forums. I watched the panasonic and samsung at more than one shop. But LG never.
The options are simple:
Panasonic - Full HD panel, reputed company, but no 3D
Samsung - HD ready. Only one third of full HD pixels. but have 3D. Here again you have to spend Rs. 3500.00 for a pair.
LG also HD ready with one pair of glass.
If you ar playing full HD video (1080i or 1080p) there is a marked difference in clarity in the panasonic. You can also sit coloser to have an engrossing view.
In SD samsung is better as it has lesser pixels. The 3D also is reasonably good.
Price of all models are comparable.
Now that more and more HD channels coming up, I my opinion full HD is the way to go, even at the cost of foregoing 3D.
If you can wait, 3D model of panasonic 42U30 has released in the west and is given its indian website. But I expect the price will be around 50 -55K.
If you wish to experience 3D, and is planning to buy a computer monitor, here is an alternative I found.
http://www.hifivision.com/television/20636-3d-monitor-lg.html