I turned down an otherwise-attractive offer last year because they wouldn't budge on five days a week in the office. My door-to-door commute there would have amounted to just about 8 hours per week (assuming the subway is running properly, which you can't assume in Boston, but let's for the sake of argument).

I told them that, since the commute would have lengthened my work week by 20%, I'd reconsider if they came up on their offer by 20%. Haven't heard back, I assume they're still thinking about it.