This 'Geek Productivity Chart' from Bruno Oliviera is surprisingly accurate at describing how I tend to work (ignoring, of course, the humorous generalization about what non-geeks apparently think): 

I'm most productive at the office from:

• 11am-1pm, which is when I'm trying to finish stuff off before taking my lunch break
• 3-5pm, but only if I'm not interrupted and I've timed my caffeine intake right (I usually have a mug of coffee at about 2pm)
• 6-8pm, which is when most people have left and so the office is relatively distraction free (though at least 2-3 people from my team are regularly there till 7pm so I'm usually wearing my headphones during this period)

At home I'm incredibly productive from about 9pm to midnight, which is when I do most of my big-picture, strategic thinking and planning. (And blogging.)