Once you play a game or watch a movie on a big screen you will never go back to a TV.
That said, you will enjoy a TV more if you plan on turning it on/off lots as a projector bulb will be easily slain if you do that too much in a short period of time. For a projector, plan on sitting down and doing your thing, then turn it off at the end of the night. Also, it's best to use a projector in complete darkness, so if you like to have a lot of ambient light, you may wish to go with a TV.
You have the luxury of having a dedicated theater room, though, so I can't imagine why you wouldn't get a projector, assuming that the things said above don't bother you. The dollar to screen size ratio puts projectors way ahead of TVs. You can easily paint a screen and DIY a flat baseboard frame right onto your wall and do it super cheap, giving you more money to spend on a good projector.
Best of luck in your home theater choice!
Video: Optoma HD3300, Panamorph UH480, Darbee Darblet, Samsung BD D6700 Blu Ray player, DIY Seymour Centerstage XD 138" Curved Screen
LCR - Tannoy DC12i, Sides - Tannoy IW63, Rears - Tannoy Saturn DC6ti Bookshelf, Ceilings - Tannoy CMS 603DC (TF), Tannoy CMS 601DC (TR), 3 Micro Marty/1 Full Marty DIY subs
Amplification: Emotiva XPA-3, Emotiva XPA-2, Outlaw Audio 7700, 2x Inuke 6000DSP
Receiver: Anthem MRX 720