Almost 4 days. The first 60 hours were kind of accidental. My friend Matt and I were playing Final Fantasy 6 almost the entire time, and we couldn't get ourselves to stop. By the time we hit the 3rd day, we just decided to go for more and tried to stay up as long as possible. It was during the summer, and we had little else to do. By the time I hit the 4th day, I was so completely insane that I couldn't even think straight.

Actually, wait...it was almost three days...I think... honestly, I can't remember. Everything after that first 48 hours is just a blur.