The Sony and Samsung LCDs that use S-PVA panels have excellent uniformity and good blacks. The recent higher end Sony TVs use this panel type (from the T3000, D3000, X series and I think the W and V series too, but not sure). The other sony LCDs use other panel types such as TN which tend to give quite noticeable backlight leakage especially in the corners. Some samsung TVs use S-PVA panels too, the R87 or R88 sometimes do for example, however, samsung are known to put different panels in the same model of TV, so one R87 may not be as good as another. To check if a R87 or R88 has an S-PVA panel, have a look at the sticker on the back, there should be a letter out on its own which will be either a C, M, A or S. If it is an S, then it has a samsung made S-PVA panel in it, ones with a C or M on the back tend to be quite poor.
The Panasonic LCDs which use an IPS Alpha IPS Pro panel are also very good at uniformity and blacks, the LXD70 / LXD700 models use this panel type, and I would assume so does the LZD, however the LMD does not.
None of these is 100% black in a darkened room though, for that you need plasma. But some LCDs are deffinitely very good.