I just took delivery of the 52" Samsung 650 series last week. Did a lot of research and comparison shopping before deciding, and I am really, really, REALLY happy with it.
Also got a Blu-Ray DVD player, and a Klipsch home theater system at the same time.
Especially with the Blu-Ray DVD's, the resolution is just flat-out scary. But even watching regular cable is a world of difference from the 19" tube set I had before.
Best of luck with your decision. Don't forget about upgrading the sound - it's half the fun! Winter's coming, so now's a good time to settle in with a good stack of DVD's...
S1