Some thoughts on active vs passive 3DTV technology. We just purchased the LG 42LW5300 3DTV bundle for under $700 from NewEgg (which is a phenomenal deal), part of their Cinema 3D line that uses the same 3D glasses as you get in a RealD equipped movie theater (the AMC chain here in Bloomington). This bundle also includes a 3D Blu-ray player, so it's basically a 3D cinema in a box.
We went with the LG Cinema 3D technology for reasons pertaining to the glasses technology. Being a home with small kids, we didn't want to risk the breakage of more expensive LCS (liquid crystal shutter) glasses that are part of the 3D systems in 3DTVs by Samsung, Panasonic, Sony, and a few others.
We also wanted to be able to invite friends and family over for viewing 3D content (either via 3D Blu-ray, YouTube 3D, or 3D channels on our DirecTV plan) and purchasing and maintaining a number of LCS glasses was cost prohibitive. Now, with the LG Cinema 3D technology, people can just bring their glasses they received when seeing a 3D movie in a theater. We also have a bunch of these glasses on hand from our various trips to the theater.
We went with the LG Cinema 3D equipped 3DTV that uses passive polarization in the glasses. If the glasses get broken or lost (very possible in a home with kids) replacing them is a matter of a few dollars or a trip to the local theater for a 3D movie viewing.