Here's what i did in my old apartment and my brand new house: I took one bedroom, put all my bills/sabres memorabilia in it. Set up the computer/home network, tv, ps2, directv receiver, my fishtank, and stereo. It's my room, with my stuff. I have a 19" tv in here, as opposed to the 36" downstairs, but you damn well better be sure that i'll be watching the bills in this room, with the door shut, and plenty of beer. Moral of the story: don't buy into the myth that you have to do everything with her at all times. You need time for yourself in space for yourself. Whether it be the garage, kitchen, bathroom, or in my case, the extra bedroom, you need your own space where she's the guest. She's got her own space and i know not to !@#$ with it, just like she knows not to !@#$ with mine.
You can keep your money seperate, use proper toilet etiquite (btw, i keep the lids closed too. that saves the argument, plus it makes the toilets look nicer) even get away for a while, but if you don't have your own place in your house, you won't last more than a week.