What is your favorite e-book format? And why?

[Faithwyn]

.lit Even though it didn't fly, it was the best looking screen text I've seen.
I've got many many books in .lit format. Hope my reader never dies! LOL

[readerdude]

I prefer pdf

[specialstevie8]

Its epub ... I can read from any device and its small in size compared to pdf ...

[RobertX]

Anyone here use I-Silo?

[nonfiktional]

Epub is like the easiest and most common e-book format. I hate reading PDFs because after a while it tends to get annoying and most fonts are nonnegotiable.

[sceadugenga]

I use an iPad to read and I have iBooks and the Kindle app on it so can read epub and Mobi formats.
Both read pdf files.
Most of my novels are in iBooks in epub, illustrated books and magazines in Kindle as mobi or pdf.

[GeyGray]

epub is my favorite 'cause it's convenient to use on telephone

[warren1970]

PDF is not actually my fav but has been around awhile

[contrail]

I prefer PDF for compatibility across devices, but epub is best functionality wise.

[cmoskiller]

PDF is the good format for any books, including illustrated books or no. EPUB is the good format for text books only. DJVU is the good format for old books (like scans of 15-19 centuries).