This whole discussion makes me feel very happy to work where I do. Basically the way our system works is that all full time employees can be paid overtime after 45 hours a week except managers, who are exempt. But even managers don't usually work crazy more hours than others.
Each employee also gets a certain number of hours every pay period that goes into a paid time off account. (most employees get 6 hours per pay period). These hours are your paid time off for sick leave or vacation. You can carry up to 200 hours at a time, they do not expire at the end of the year, and any hours you rack up over 200 are cashed out to you at your hourly rate.
Basically I work my 40 and leave unless there is a big push on for a project, then I will work some extra. But at most I am working 5 hours a week for free, which is a fine tradeoff in my opinion, and rarely happens when I manage my time properly on a project. But sometimes it can't be helped, and management knows this.