@ OP,
What is your budget ?
How many are watching at a time ?
Planned size of the TV ?
It is true that there are certain serious difference between the active shutter 3D that Samsung, pansonic etc promotes and passive 3D that LG supports.
If you are going to buy the TV soley for 3D and you are an avid fan of 3D definitely, the passive 3D from the LG is the way. But remember that the cost will be much higher.
If you are going for a new TV and interested to have 3D on it, then definitely 3D plasmas are the answer. This TV will give you excellent pic quality on 2D, that the LGs cannot match. But you need to content with the two 3D glasses that are supplied with the TV. In any case, the 3D contents are limited and there is no harm in splitting the viewing among the family members to save money and have a good TV,
As you are fortunate to have a neighbour with 3D TV, do a demo for all the family members to find whether they are facing any problem with active 3D. If the TV is of any previous year models, try current year models at some shops, they are reported to be much better in 3D.
In either case, where is the 3D content?