Well, my wife is more into movies than I am, though she'd be happy with two channel playback through the TV's speakers. I want a high-quality stereo system for music. But, when it comes to other things, I want high quality too, so I won't settle for "two channel playback through the TV's speakers".
That does cause a bit of a dilema because, while my wife likes the idea of a theatre, she doesn't see the need for better speakers, a subwoofer, a decent pre/pro... until she hears the difference. Purely technical improvements, like my Odyssey Stratos amp, therefore, are a hard sell.
I'm pretty much settled on BG Radia R32i inwall speakers for surrounds, but at $1k a pop, and $1800 for a centre channel speaker, along with a stereo and three mono Stratos amps, that totals $10k, $6.8k if I do 5.1 first and then 7.1, which I probably will. Last will be "a real" projector and screen. I am tempted to add three more R32i speakers for front L/C/R inwall, or two R75i/R8i and one R32i -- only to have a complete built in theatre -- that would make sense if I got a ceiling mounted projector.
Of course, that's a lot of $$$, and isn't going to happen any time soon
But, one can plan (and dream).