I live in a three bedroom house with five other adults, two nomadic cats, and a needy dog.  And it's not nearly as chaotic as it sounds.  As with everything, it has it's good and it's bad aspects...

On the dark side:
-- We only have one working shower.  Pair that with four long-haired (and one long-bearded) individuals, and the fact that I was astoundingly brilliant in avoiding all other cleaning responsibilities by declaring the bathrooms "my space", leads to daily straightening of the bathroom and weekly "hair babies" out of the shower drain.  Thankfully, other people have taken on the dishes, which I hate even more.
-- We all keep different schedules.  But we're respectful of the noise level.


But, on the bright side:

-- Everyone here loves to cook.  Someone is cooking something delicious every night of the week.
-- Each person is only responsible for 1/6th of the rent and utilities, and saving money is always nice.
-- Everyone is willing to help in some way if someone needs something (be it a bit of help with bills, a lot of help with home improvement projects, or a partner to work out with).

    So how do we make it work?  The easiest answer is that we managed to pick roommates with similar tastes and values. We all like and respect each other and we're extremely open with communication - if you let a little annoyance go without talking about it, it will fester and grow into a large problem.  We started a shared Dropbox, linked through everyone's computers and phones, where we put our shopping list and update once something is in the cart (it took ending up with two gallons of yogurt, five gallons of milk, and more chicken breasts than I care to admit thanks to three of us unknowingly shopping at the same time to reach this revelation, but it was definitely necessary).  We also have a whiteboard near the door, where we write whatever everyone owes on bills as they come in and general communication.

   It's not perfect. We don't always get to shower when we want and occasionally someone will let the dishes pile up.  And we all have our bad days.  But, for the most part, we've managed to find a rhythm with each other.  I get a good amount of me time, but I'm never lonely.