I've got a 51 inch widescreen Hitachi Ultravision (RPTV). I paid about $2300 for it a little over a year ago. I am completely satisfied. I would not get any sort of flatscreen at the moment, as the technology is still evolving, and it is not clear which flat panel technology will become predominant. RPTV is a mature technology, and if you can deal with the size and limited viewing angle issues, they have a great picture.
I have about $4k tied up in the audio side.
I have a hi-def cable box, and watch several hours a week of hi-def programming. Sporting events and the Sopranos are great in hi-def. I can't wait until more content is available.
Mark