I prefer paper books but I basically read 80% ebooks.
It's cheaper; it's more comfortable when I'm reading long books or when I'm in bed and I'd need to keep a light on; I also have a commute and in general, I'm often traveling on public transportation, so an e-reader is easier to carry than a physical book; and last but not least, I read in more than one language, and I don't have to deal with the hassle of ordering books from other countries.