If your going to buy a plasma, your only consideration should be a Panasonic since they dominate the plasma industry since they bought out Pioneer's plasma tv division (Pioneer used to make the best plasma TVs).
I personally just bought a 720p 42" plasma just because of the price and the reviews of the model. As well I opted to go for 720p instead of 1080p because at 42" it's really hard to see the difference. 1080p only really matters when your considering 47" or higher. As well the refresh rate on a plasma is must better than on a LCD since there are still issues with Ghosting. As well, plasma burn-ins are pretty much a thing of the past. Newer Plasma TVs have built in pixel orbiters which ensures that this doesn't happen and if it does, then you got yourself a lemon.
If your considering Plasma, then Panasonic
If you are considering an LED TV, then I suggest Samsung since they were the ones that pioneered the technology.
If your considering LCD Samsung or LG