I already have a 32 inch Sony LCD. Now I had a requirement for a big screen (40/42) for my living room.
My choice were Sony KDL-40NX650, Panasonic TH-L42E5D and LG 42LS5700. After a detail research of one month on net and comparing them side by side in different shops I went for LG 5700.
Reasons:
1. LG : S-IPS // Sony : SPVA // Panny : IPS (alpha)
S-IPS panel has a very wide viewing angle, matched by uniform backlighting and a moderately reflective screen
2. Panny & LG : 42" // Sony : 40 " (gain 2" extra)
3. All these TVs produce sharp image but LG's picture is crisp and color is most accurate. Brightness of Sony is better but I think no one can see so brightened picture in there home. LG's brightness is sufficient for home, even it requires to reduce the brightness for normal viewing.
4. Black level of LG and Sony are almost same. After some adjustment LG produces great inky black even than Sony.
5. Panel refresh rate of LG, Sony & Panny : 60 Hz. But LG's 'Motion Clarity Index' is 200, Panasonic's 'Backlight Scanning' is 150 and Sony's 'Motionflow' is 100. LG handles 24fps frame rate with mostly judder-free motion much better than the Sony.
6. LG : 3 USB // Sony : 2 USB
7. Panny & LG supports maximum video formats including mkv and can access flash drives and external HDD (FAT/NTFS) but Panny takes a long time to access the drives and do not upscale the video. LG takes no time to access USB drives and upscale the video. // Sony neither support mkv nor support NTFS.
8. After sale service of Panny is poor than LG and Sony.