I think, assuming that the schools are ranked within, say, five or ten places of each other, that culture of the school should definitely be an important factor. It's not just about being happy, or about going to school in a region where you'd like to work. I've heard time and time again from lawyers that the people you go to law school with will be your future clients and connections and a great source of business. If you go to a school that's a bad fit for you, the chances that you will make those close connections are lower. Obviously, any normal person can find a small group of friends at any school, but if you're on a school's fringe rather than tied into its mainstream culture, you're not going to be able to reap the rewards of a significant social network down the line.
I say this as someone who might end up choosing Berkeley or University of Texas over Harvard. Yes, seriously. I'm hoping to get accepted to Stanford or Yale to have the option of staying in the "top three", but I am willing to take a rankings drop to get a) a substantial scholarship and b) a school culture that fits me better. And I feel I would be justified in doing so.
Now, all of my decisions revolve around schools that are more or less T14 or T20. I definitely don't think you should choose a school ranked, say, 80, over one that's ranked 20 just because you fit in better. There exists such a diverse range of schools in each rankings range that you should be able to find a good fit within the highest range you qualify for. And if you only can make it to a third-tier range of schools, as has been said here before many times, you might want to think really hard about law school.