The Sony and Samsung panels are made at the same factory but split production lines, or something like it, so Sony TVs do not have Samsung panels.
I think the current Sonys are pretty decent, whereas I have yet to see a Samsung that has impressed me, and I have seen loads which I thought were gash.
Particularly I think their picture processing (upscaling, etc) is poor, and anything that isn’t good HD is mess to my eyes.
I always used to say Panasonic, but I read something that put me off, but for the life of me can’t think what it was 🙁 They are probably still a good bet though, and have been impressed with a few.
Personally I am not sure about Samsung reliability, but neither am I about Sony – so I always make sure I get a decent warranty – maybe John Lewis for the 5 year.