Opentype or Truetype? What's right for you?
They both work on Mac and Windows. And while Truetype is the tried-and-true format, Opentype has some neat new features that are quickly making it the industry standard.
Opentype has all the features of Truetype, but it can include autoligatures, which are actions pre-programmed by the font designer that cause stylistic changes to occur while you're typing. For comic book fonts, this is most often seen in some dialogue fonts when you type a word with two consecutive, duplicate letters; like the two o's in "book". The autolig can make the o's look slightly different from one another, creating a more organic, hand lettered look.
It comes down to personal preference, but I always suggest Opentype.