Totally depends on the area and conditions for me. I have strictly morning locations and strictly evening locations and hunt them based on wind direction, food source and time of the season. Took my youngest son to one of my morning location yesterday and he killed his first deer there at 8:00 AM. (6 point, he was thrilled). Took my oldest son to my afternoon/evening location today and he proceeded to miss an 8 point at 3:30 PM. (he has killed 5 bucks previously at that location between 1 and 4).
If I had to categorize all of the times I have killed deer, (and elk, caribou and antelope), I would have to say that I have killed more in the morning and generally the biggest at mid day.
I think I've killed more deer in the evenings, but it is pretty close. I've probably seen more deer in the mornings, but I've also passed on more deer in the mornings. Maybe knowing I have the evening hunt makes me picky in the A.M.
Mostly hunt mornings (just too many potential problems at night) and have had no trouble filling my freezers. The 8-9 o'clock hour area seems to be the best year in and year out
I usually see most of the activity between 7am and 11am. I usually harvest a deer during that time, and am leaving the woods before dusk. I hunt public land, and at 9am when the pheasant hunters start shooting, the woods become alive with activity.