The actual "Record" is 2 Weeks with little to no sleep, which caused Death in a Minor due to his Mother forcing him to stay awake, bound to a chair throughout the entire night.
Yes Parents can be screwed in the Head too.
That being said, i once managed 2 1/2 Days, or 60 Hours straight without Sleep, simply keeping going by Willpower alone, and the lazyness to actually go to bed. By that Point i wasnt as sleepy as one might think, you literally get to a state where you are so tired that you arent anymore, its like you overshot the "im sleepy so i better go to bed"-phase.
Of course there are side-effects, not sure which apply, given that not everyone would actually get the same ones, i.e. one might be hallucinating after day 2 while another guy only gets there after day 5, to use that as example.
I actually went to bed after the 60 Hours because, while not actually sleepy in the normal sense, my behaviour started to frighten me. Im by no means a very nice Person to begin with, which apparently only gets worse the longer im awake. So yeah, you may learn something about yourself on the way there, which potentially you wouldnt like to know.
Quick Edit: Oh and you may as well factor in a increase in Hunger and Thirst. Which means you will eat and drink more because your Body is requiring the Energy Intake to keep going. Which is essentially what Sleep is for, its a "Battery Saver", i.e. if you dont save energy, you have to keep adding.