Been working in my company for almost 6 years in NYC; joined right out of college. We do comparable/competing work to the Big 4 (forensic accounting, financial investigations, restructuring, corporate finance, litigation support, PR). I'm in the litigation support/e-discovery group. When I first joined I was pulling 12-14 hour days and weekends very regularly. Everyone in my group was doing on average ~70-90 hour weeks; this went on for about two years. However, i've become a manager in my group and it's gotten a lot easier now that I can delegate the work. On average, I have 40-50 hour weeks; I only work at most ~60-65 hour weeks for a month or two if a tight-deadline case comes through and even that's getting stressful. It's not the job I love but I get paid fairly well and the hours are fairly normal.
I'm with others on the board. If you don't have a passion for the job or the job isn't going to get you to that position you are passionate about, working crazy hours isn't going to help you move up in the world. You'll only burn yourself out and end back in square one.
The other groups in my company (forensic accounting, corporate finance etc.) still work 70-80 hour weeks. God bless em. They run on a much more Big-4 like model.