[HogwartsExpress]

1. Epub
2. Mobi
3. PDF
4. DJVU
5. Other

And what is the reason you like that particular format ?

First one

Epub because I can use any e-reader.

Epub.
I remember when I got my kindle and I uploaded a few PDF books I had downloaded over the years and read or begun on my computer and the format was all effed up. It made me so mad to convert everything ahah

[nutpants]

Epub OPEN source free format
Then djvu another open-source format.
I avoid pdf like the plague..

[poojasona]

Epub all the way!

PDF

EPUB supported by all ereaders, allows upscaling text properly (which PDFs do not).

EPUB all the way.

And what is the reason you like that particular format ?

98% of the time with e-books I want flexible layout, so I can choose the font size, flow text to the size of the device, etc.

epub is the easiest format to work with (it's essentially just HTML with some metadata) and supports flexible layout well. And it's supported by the widest array of readers.

Plain text is underrated; it's fine for a lot of things. Not ideal, but not terrible.

PDF is only appropriate in the very limited cases where physical page layout is integral to content; epub3 can handle fixed layout but isn't widely supported yet. It's great as an intermediary for printing (where physical layout is obviously critical) and for certain layout-intensive applications, but I'd rather have even a plain text file than a PDF for a typical novel. The text file I can convert to an epub comparatively easily.

mobi is locked to Kindle and less flexible than epub, but it's relatively easily converted without much loss. There's no real reason for it to exist in my world, but it's not a big obstacle. azw is more of a pain to convert, so much less desirable.

djvu is a pretty nifty open format for scanned documents, but if you're going to purpose-build an ebook then it's a bit of a square peg. And it doesn't have broad support.

Definitely the Epub format.

[HogwartsExpress]

EPUB supported by all ereaders, allows upscaling text properly (which PDFs do not).

But Amazon Kindle doesn't support EPUB.

Epub and if not then mobi. Any other (mainly pdf) gets converted to epub unless it messes up the format.

EPUB mainly because I am familiar with its HTML roots ... PDF is the worst ... it is basically a graphics format and sucks at text I have stopped even grabbing anything in PDF .. even after conversion it never flows right .. unfortunately its all too common ....

Grab CALIBRE its a free proggy that will easily convert epub into mobi that can be used by kindle ....