Im looking to finally complete the mancave in my house. I know which receiver to get. Buying the Onkyo 609. But now need a tv55 inch is my limit. It has to have 3D only for the fact that lots of movies I enjoyed watching in theaters I want to see at home in 3D. The tv will be in the basement with barely any sunlight coming in. I wont have any gaming for it and will be a primary special events, movie night and football tv.
Congrats on your Giants.....I hate you but will try to help anyways (I'm an Eagles fan).
Get an emerson hand held 7inch portable
In general large plasmas are significantly cheaper than LED tvs, they generally have better blacks (but LED with local dimming is excellent as well), LED-LCD is brighter. Plasma tvs main negatives are very reflective (some lcd or led-lcds are like this too...just depends on the screen), they draw more power, they are heavier, there is some image retention (not permanent and less of an issue now).
LEDs tend to not have quite as good viewing angle, edgelit LEDs are less uniform, not quite as good at motion...though less of an issue nowadays with 120/240hz. Better for use as a computer monitor than plasma.
For 3D you should decide on whether you want active or passive. If you plan to have a lot of guests and need lots of glasses, I'd go with the passive even though it's more expensive upfront. Once you decide that, it'll limit your choices a bit and others can give more recommendations. I'd probably look at samsung and panasonic for mid range/more upscale and LG and Vizio for a cheaper option. LG passive tvs have gotten some real good reviews lately.
Epson3010 projector with an electric drop down screen so you can double your limit to 100" at the same price that you have been considering. You can fit that screen into your ceiling or on a wall, so it can fit. Think about it, talk about special events, and in 3d.
By the way, you can get active glasses for it at best buy for $50 each, or could when on sale, so you can have, say, 6 counting the 2 that come with the projector.
If a lot of your viewing will be in cave conditions; I would suggest one of the high end plasmas. Panasonic VT30 or Samsung D7000, D8000. The perfect screen uniformity and black levels far exceed LCD (except for the Elite) in low light conditions.