Probably March. It just lacks in any events. Spring Break usually occurs in April and most campus events occur in May as well.
I can never hate January because my birthday and my Mom's birthday fall within that month + I'm usually off from school till February at the college I go to.
I don't dislike any particular month, but if I had to choose, it would be November. All excitement of being back to school is over at this point, and there are no holidays (in Canada).