I'm most productive in the period an hour or so after I get up. But I hate getting up early. What normally happens is that I'll get up at about 7/7:30, feel like crap for an hour, have about 3-4 hours of super-productivity where I'm completely alert and attentive, then gradually wind down through the rest of the day. I used to not be able to get to sleep before midnight, I liked staying up late so often; but now, because of work, I've somehow managed to force my body to fall asleep at around 11/11:30. Which is good for my well-being, that's for sure.