Midnights are okay for a while, especially if its a long shift every other night, so you still have some nights for other stuff. I wouldn't want to do it again unless for short term and a considerable cash influx.
I prefer mid-day or evening for the long haul. I find there's a big difference between getting to sleep by 6AM as compared to 7AM or later in terms of the quality of sleep. It's especially difficult to stay asleep all afternoon in the spring & summer when it's hard to keep the place dark and cool enough.
When I was driving, I really liked 11-7, 12-8 or 1-9, as I avoided rush hours and still had time to do other stuff around work. But now with the TTC, working 12-8 really means 10:30-10, so I prefer evenings after 3PM. At least I can do shopping, banking & stuff on the way to work, and still have a few hours after Midnight as well.