I am looking at a Sony Bravia 50" LCD and a Panasonic vera 50" Plasma.. given all of the known differences.. which would be better for a computer monitor using the new mac mini and hdmi?
Mac Pro Quad 2.66 Xeon 9GB 1TeraHD,
Mac OS X (10.6.2),
Logic 9 Studio (64 Bit)
They're both going to be equally bad. The plasma will give better color, but also use a boatload more energy in doing so.
In the end though, HDTVs have a maximum resolution of 1920x1080, and it doesn't matter if it's a 24", 50", or 72" set... Same number of pixels. Only differences are either the size of the pixels, or amount of space between them.
HDTV brought things a long ways forward, but they are still nowhere near suitable for use as a monitor. Monitors can make for good TV sets, if you're willing to give up some of the point and click remote operation.
As a general rule, I would recommend an LCD over a plasma for this type of application. The main difference being that a plasma can suffer from image burn but also they exhibit something called large area flicker when there is a lot of white on the screen, as is often the case with computer output.
But I agree with Scott; neither one makes a very good computer monitor if that is to be your main use.
I would tend to agree with LCD over plasma. I am going to guess since you are talking about a 50 inch TV, this isn't being used as a regular desktop computer setup. Regardless of a maximum resolution of 1920x1080, if you are sitting 5+ feet away from the screen (and I'm betting it will be much more) it won't matter so much. Your main issue with that display setup will be getting your font smoothing right.
More important even than panel type is the adjustment abilities of the HDMI input. If you can use separate audio connection(s), and how you can adjust the image scaling will be more important to getting your mini's desktop to display correctly on the TV.