There is a website where you would be able to compare models of LG televisions. The website is located on the official LG website, in the upper right hand corner, under 'Home Entertainment'. There you will find all of the LG Television models.
You can compare LG mobile phone models on there website where all of their current models are available to look at and compare the features of the different models.
There are a number of LG 3D televisions on the market. All use passive imaging techniques which places them all in a similar class. The models vary in size and features but a more useful comparison would be to compare the lower resolution passive models from LG with the full HD resolution active televisions by most other manufacturers.
The Samsung 37" LED Television is the best in quality, the LG is the best value and the Visio has the best price according to reviews. Plasma TVs have wider viewing angle than LED TVs and are considerably cheaper.
LG only make passive 3D television. They do not supply any models that are active 3D.
LG televisions use passive glasses so you will not find LG active glasses. Actually, LG has made several models of active 3D televisions, despite their current push for passive. LG glasses such as the AGS100 will not work with Samsung televisions. If you are looking for lower priced glasses for your Samsung TV, try the Monoprice website.
LW6500 LW5600 LW5700 LW 5600
On the internet, LG LCD televisions can be purchased at the official LG website and Amazon. They can also be bought at a discounted price in Best Buy.
LG calls its 3D technology Cinema 3D so the 3D models all use that title.
Television reviews can be found on the Review centre website, Shopzilla and Crowdstorms' TV reviews page. Also LG has a lot of useful information on their own website.
Cinema 3D is the term LG uses for their 3D technology. This does not apply to all LG models. Only the passive 3D line in models that start with LW. Ex: LW6500, LW5600.
Those companies that you mentioned are all good place to try to get an LG TV and there are many other retailers that sell them as well. Compare prices between them.
White OLED refers to the LG technique of adding a white LED to the red, green and blue LEDs in their OLED display panels. LG claim that it produces more faithful reproduction than just using red, green and blue elements. Whether or not that is the case is a matter of opinion. Before investing, it is always important to audition several models of television. Compare LG's white OLED screen to other OLEDs and you can decide whether LG have made an improvement.