Why would comic sans be banned?
As the name suggests, it's a sans-serif font for comics, and I daresay it's one of the best fonts around for that. The font is excellent for speech balloons, it's lose, random, and very readable for short texts.
However, I've had electrodynamics lectures in the damned font. It might be one of the worst fonts for that, because it's hard to read.
Any thing on a screen, arial or verdana is the best. Also, that supposedly serif fonts are better readable for body texts is a myth that has never been proven. It apparently originates from one research which had one sans font, which was the hardest to read of all.
http://www.alexpoole.info/academic/literaturereview.html
As it looks, the readability of different typefaces seems to differ more between individual members of either family, than of some of both. Typefaces that are easy to read are arial (sans), helvetica (sans), times (serif), verdana (sans), computer modern (serif).
Typefaces which are hard to read are lucida console (serif), impact (sans).