When it comes to Plasma then you should definitely be looking at Panasonic. They have consistently made the best Plasmas for years now.
I ought to justify my statement. I work for a company that sells 1000s of plasmas and LCDs every year (to retail). We get to see most models and makes here (and observe their performance in the field).
Panasonic arguably make the best LCDs too - they are certainly superb. Whoever said in the other thread that Samsung make the best LCDs was talking crap. They aren't bad - perfectly acceptable - but not amongst the best at all (I do own one of their small LCD TVs though).
Philips were great CRT TV manufacturers but haven't shone in the Plasma nor LCD markets. They are getting better though.
Sony are consistently good. Their LCDs are very good.
Toshiba are also pretty consistent.
LG I'd put in the same category as Samsung. Good, functional, shouldn't cause any serious problems and reasonably priced, but not among the best.
I've heard literally thousands of conversations between our techie and sales guys. You tend to pick things up in that situation.