Samsung is the market leader,it was always cheaper to buy then Sony.
They were the first to come up with the name LED for a edge-led lit lcd.People thought it was something new.When infact led backlight tvs were old infact the first so called backlight LED tv was launched by sony in 2004 ,they still called it lcd.
But this year not all the models of samsung are cheap they are infact many models are more expensive then Sony including there flagship model.
As far as performance goes for most years the top honors went to Sony.
You have the XBR4/X350 vs samsung F96 year 2007
You have the XBR8/X450 vs samsung series A9xx of 2008
You have the XBR8/X450 vs Samsung B8500 of 2009(honors went to samsung).
You have the HX900/909 vs samsung series 9 and series 8 of 2010
And this year you have the HX925/9 a full array local dimming led-lcd with highly revamped image processing vs the edge-led local dimming D8000.
That market share is quite old currently the last known data for india was the Sony was the market leader in flat panel display.
Sony Takes Top Share Position for Flat Panel TV Shipments in Q210 for India - DisplaySearch
Globaly speaking Sony is either second behind samsung or perhaps behind LG based on different market research websites.
Flat Tv | Sony Ranks 2nd In Global Flat TV Sales In Oct.-Dec., Overtaking LG
Samsung Leads In Global TV Market Share: DisplaySearch - 2011-02-22 16:26:35 | TWICE