My unfair snap to judgment knee-jerk impressions of fan bases:
Ohio - The most loyal, passionate and largest and it isn't even close. I sound biased and cocky but I don't know how anyone could deny it. Unmatched school pride.
Toledo - The next best. One of very few MAC programs to have a following outside of just students and alumni.
Western Michigan - Cynical but solid, a strong core group of fans.
Ball State - Generally pleasant and would be supportive of even a mediocre team if they could just get it together.
Akron - Incredible run has led to a solid fan base (albeit kind of pompous and/or ignorant in spots) but I wonder how quickly they would flee if and when they fall on hard times.
Buffalo - Biased dreamers, hot and cold. At least some passion. Least amount of conference pride, it seems.
Bowling Green - Very little school pride but support is decent when the wins are there.
Kent State - Ditto.
Central Michigan - Sort of bandwagon, but some solid fans.
Northern Illinois - Pure bandwagon.
Miami - Non-existent, nearly hopeless.
EMU - Non-existent, hopeless.