Another top-end 32" panel that is worth considering is the LG 32LG70
whose release appears to be imminent.
As far as the Sony, Samsung and Panasonic are concerned - each has their strengths and weaknesses, so I don't think there is a clear winner and personal judgement must be made on your own unique situation and planned usage.
Here is a little table of how I think the models compare, but I should note that I have not yet seen the LZ800 in person yet (which is the main reason why I haven't already bought it
Color Blacks Sharpness Motion Sound Off-Angle PC Support Gaming
Samsung LN32A650 Excellent Good Good Mediocre Poor Poor Good Good
Sony KDL-32XBR6 Good Good Excellent Excellent Excellent Mediocre Mediocre? Mediocre?
Panasonic TC-32LZ800 Excellent Excellent Good Excellent Mediocre Excellent ??? ???
To summarize what I gather to be each model's strengths and weaknesses:
The Samsung LN32A650 has an excellent, vibrant image, but this is tempered somewhat by its mediocre motion handling with noticeable blurring in fast moving scenes. Also, the poor off-angle viewing angles and very noticeable reflections from its glossy screen make it less well-suited to a broad variety of room layouts. PC support and gaming is also a strength of the Samsung with good response times, a dedicated gaming mode and various modes for 1:1 pixel mapping through DVI->HDMI. The built-in sound of the Samsung is rather weak.
The Sony KDL-32XBR6 has a slightly less vibrant and overall more muted picture than the Samsung and Panasonic, but this is offset to a certain extent by a somewhat higher level of sharpness and detail. Motion handling on 24p film sources is excellent, while not quite as good for broadcast and games, but still better than the Samsung on all counts. Its off-angle viewing is again better than the Samsung, but not nearly as good as the Panasonic. Two clear advantages that the Sony has over the other two models: significantly better built-in sound and the least reflective screen finish. However, there seem to be some question marks about the Sony's suitability for PC and gaming use with reports of problematic PC video display and gaming lag.
The Panasonic TC-32LZ800 seems to the clear overall winner in PQ among the three, although perhaps with a touch less sharpness and detail as compared to the Sony (edit: and perhaps slightly less vibrant colors than the Samsung). Motion handling is excellent and the off-angle viewing is easily the best-in-class. There are potentially problems with the reflectiveness of the panel, however, so this should be taken into consideration. The built-in sound for the Panasonic is only mediocre and its suitability for gaming and PC usage are totally unknown at the moment.
From your description of usage, it seems that all three models would be entirely satisfactory with perhaps the slightest nod to Sony (especially if sound is important) or Panasonic (especially if off-angle viewing is important) over the Samsung. However, there is no replacement for evaluating these sets yourself in person and if you are in no rush to buy it might be worth waiting to see what LG's 32LG70 offers.