I can comment only on the LG service - again that may vary depending on the location - my feedback is based on my experience in Bangalore.
My 1st LCD TV was a Samsung one, had horrible experience with service when my panel started giving problem. So I switched to LG (42LH90). After about 4 years of use, I had an issue with the power supply, raised a onsite-service request from the LG website. A technician called & came to my place the next day, checked and found the power supply board had gone bad. He then checked and confirmed the availability & price of the PS unit, it was available for 2200/-, so with my consent he ordered for it in front of me. 2 days later, the technician called & came again, with the new PS unit, fixed it, thoroughly checked it and then asked for payment with a receipt. I was very impressed - within 3 days after making a online complain, my TV was up.
I also had a very good experience while getting this TV installed 4 years back. The service guy actually came few minutes before the TV set was delivered to my place. He came with the wall-mount, installed the TV and shown me all the menu options. Contrast this with Samsung - where I had to wait for a week to get the TV installed with wall-mount, I must say - from my experienec - LG service is way better than any other brands.
My exp with LG service is always pleasant. The result of that, my fridge, washing machine, micro oven and smart TV is all LG. They offer fantastic service.
Let me share one exp when I bought my LG LED smart TV. In 2 to 3 weeks time, my TV blewed up (due to voltage issue and didn't use an stabilizer). I luckily called up the LG service guy (deputed for that area) and he came visited and to my shock he informed that the panel is burnt and needs to be replaced and is not covered under warranty. Costs around 25k.
I was clueless, then this guy told, sir there is a way. Go for a extended warranty with LG itself, so that your TV will be covered for such cases.
But how will that work when the TV is already blown up.
Do not report the problem to LG service center right now. Just apply for the extended warranty, and then report the problem after 2 weeks, so that you will be covered.
Guess what, it worked.......got the panel replaced for under 4k.
LG offers one of the best after sales service in India.