I find RTF gives the least amount of hassle. FBReader has problems with the tabbed HTML format, Palmbook format occasionally produces weird characters and I never got Microsoft Reader format to work (honestly, I don't even know if FBReader supports it). The zipped RTF version is small enough, and opens without a hitch in FBReader. The added bonus is that it is much easier to ste^H^H "borrow" material from an RTF file to embellish one's own work.

I just realized I forgot to add unending praize for the magnificent FBReader program in my original post, so y'all consider it added now.