Well, unfortunately, it's available by prescription only, but...
Modofinal, I believe is the name - the newest wonder drug out there
Originally tested for combat, it helps people stay awake for extraordinarily long lengths of time. Taken every eight hours, it allows you to stay awake for up to 90 hours straight, with no reduction in your mental abilities. In fact, they tested some people after 40 hours of being awake, and they performed better than many people do after only 12 hours.
As far as the amount of sleep required after 90 hours of being awake? A nominal eight hours, then you're set to go again.
How I wish I could have some... legally, of course
Do you have any idea how productive I could be if I could stay awake and still have full mental capabilites for 90 hours?