Just built an extension with a 9x5 mtr multi use room with the intention for proper home cinema.
Got a 106" Optoma screen (electric roll up ) Epsom HD 3 D TW6000 projector.
Audio is Yamaha rxv671 and monitor lcr265 in ceiling speakers with a velodyne sub.
Set it up over the last few days - it rocks.
Gaming and blu ray is the main use but have a free view box hooked up for occasional tv use.
Got an iPad2 running the Re software for universal remote/ automation.
Sonos hooked up also.
Really happy with it.
Off to play some Battlefield 3 with actual size characters.