60+ hours. No bullshit either.
When I was younger I used to run a gaming news site and was also into the modding scene of a certain game. This meant that often I'd work during the day then switch over to pick up modding work with friends in the US on voice chat then when they were going to bed it was back to work.
At a certain point I ignored the stuff I had to do during the day trying to meet an agreed deadline for the mod and went all the way through with only microwavable pizzas, coffee and cigarettes. Somewhere around December 2002 or so. The mod hit its deadline though I spent more than a few hours debugging code that I legitimately don't recall writing nor did any of the comments make sense. One of my comments for some reason was a diatribe about carrots the vegetable because I didn't like the carot operator (^).
Actually joined Bluemoon's team on 2008 still suffering from insomnia where 2 or 3 hours a night was average to good and it rears its head every now and again though by no means often as it was. Seemed to get its shit together a few years back.
Though those very often 30+ hour no sleep sessions were horrible, I sometimes still miss being sat in my flat listening to those crap radio stations you used to get on the very first Freeview boxes and watching Bravo's 2am-4am lineup of defence industry programs about military tactics, history and future weapon design.