Fonts with the grey 'F' next to them are the ones that are free of indie creators to use. Mighty Zeo 2 is the font I'm using for dialogue in my comic project, Bluejay and The RUSH.
If you are an independent comic book creator or small independent comic company here is a great site for you Blambot.com. This site was brought to my attention by The Legend of Will Power creator, Vince White, Thanks Vince. There are many fonts to choose from covering dialogue, sound effects and design. So go get your font for you projects now.
Blambot also provides articles. This one on comic book grammar by Nate Piekos, is pretty much the guide I'm following for lettering my book Bluejay and The RUSH. This gives you a good idea on which type of lettering to use and where it would work the best. Its also helping understand which type of balloon to use in which circumstance.
The font I created with FontStruct.
For those who want to create their own font FontStruct.com provides you with a free online tool to do just that. The only thing you have to remember when creating your own fonts, online shops like Comixology can turn down your comic if they feel the font is not legible. For dialogue fonts Blambot may be your best bet. Another cool feature after you sign up to create your free account, is you can download fonts created by other member of the site. But be aware that the fonts have license file in them. As long as the font allows free use in all projects including commercial ones there should be no issue using them for your books.
Finally, Fontspace is one repository of free fonts that creator can use for their projects. As with FontStruct their are licence files in the fonts be sure to read them to know what you are allowed to do with the fonts. Fontspace list all the free fonts available on Blambot. So if you are and independent comic creator these are the best sites you can use to get your font on. Good luck folks and enjoy. Best of all the fonts are free like hugs.