The most for me was 68, working two jobs, my regular full-time office job and my part-time stint at a chipotle on a week when they scheduled me for more hours than I requested. I was so sleep-deprived and my body hurt all week. I don't know how anyone can work much more than that in a week and not completely fall apart.
Edit: yikes, reading responses and feeling like a lightweight, which is sad because no one should have to work that many hours to live. I'm fortunate now to have a stable career with good work-life balance (school job: around 40 hours a week with 3 months off a year), and it's amazing how much more time for sleep and hobbies I have!