I'm on the first floor and have tall, concrete ceilings so the only neighbors that matter are the ones next to me.
If we take the sub out of the picture, would it still matter which side I set up the rest of speakers on? On the shared wall firing away, or across the room firing towards it, or are they not low enough frequency to matter? If that's the case maybe I can still go with the entertainment room idea, just sans subwoofer (or at minimal volume)
I've lived with this setup in 2 other apartments without any problems, but the setup/layout I had was always in a living room where I could avoid shared walls...and perhaps my previous neighbors didn't care as much since it was a building with mostly college student.
Edit: Found a number of other topics asking my same question, and it sounds like it doesn't matter that much either way, though farther away firing towards may be slightly better.